chem1 54_5  J J WARREN 1982 s=0:c(10 ) %n=110 :c(n)=0:n ('b$=" " 2>:g=13:s$:m=07:a:s$+m,a:m:g 7"a",0,0,0,255,255,0,0,0,"b",0,0,0,127,127,0,0,0,"c",0,24,12 ,254,254,12 ,24,0 n<11 140 ?m$="3"m$="4"960 @n=110 B s=s+c(n) Dn Ha("Excellent."s=10 )+("Very good."s=9 )+("Well done."s=8)+("Good."s=7) pDs=5s=6"You need to spend more time on this topic." zOs<5"Your very low score indicates a poor understanding of this topic" :'"You correctly answered ";s;" out"'"of 10 questions."'' is<5"You need to read through your notes and text-book again,"'"and then re-run this program." 21004: m$="1"s=10 960 K"Do you want to go through the questions in which you made"'"mistakes?"  1000 i$="n"960 m$="4"  n=1  140  *"Do you want to run the program again?"  1000   i$="n"  10 621,0;"Type y or n. " ""1015 =""1020 i$= i$="y"i$="n" ,21,0;" Please type y n." $ 1015 V "Well done, you were right.": "No, You were wrong.": T20,0;"Type e for explanation/comment otherwise press the ENTER key." ""2010 =""2020 =13 "e"2010 :l$ Nx=0o$="true "x=1t$="true "3500 +500*n+502*x  l$'' #3600+500*n+502*x  21004 * 4621,0;"Press the ENTER key to continue." >""2110> H=""2120H M13 21004 R T"A change is described as a"'"physical change if no new"'"substances are formed": Y"Changes such as water boiling"'"and salt dissolving in water"'"are physical changes": "The term ""substances"" in this"'"context refers to either "'"elements or compounds."''"The statement is effectively"'"the definition of a physical"'"change.": 6"Boiling is a change of physical state - no new chemical"'"substance is formed."''"When substances like salt or"'"sugar dissolve in water, no new compound is formed. The salt or sugar particles just mix in withthe water." ;21004: @"However, zinc dissolving in"'"hydrochloric acid is a chemical change."''"New substances (zinc sulphate and hydrogen) are formed.": h"You cannot give a reason for a definition or commonly accepted term."''"Scientists have simply agreed to use the term in that way so that they can understand each other.": 5o$="true ":t$="true ":e$="not correct":150 J"The melting of ice to form wateris an example of a chemical"'"change": ."Heat energy must be provided to melt ice": "The melting of ice to form wateris a physical change."''"No new substance is formed -"'"ice and water are forms of the same chemical compound."''"Melting is a change of physical state.": *O"Attractive forces exist between the water molecules in ice."'"These forces hold the molecules in an orderly crystal structure."''"Heat energy can overcome these attractive forces. Then the "'"molecules can move around freelyas liquid water."''"The molecules are not broken, just separated. No new chemical substance is formed.": *o$="false":t$="true ":e$="":150 d"The change which occurs when"'"magnesium is burned in air is classified as a chemical change": J"Magnesium reacts with oxygen"'"from the air to form a new"'"compound": "Silver-grey magnesium metal"'"burns with a brilliant white"'"flame to form a white powder."''"A considerable amount of heat is given out, and the change"'"cannot be easily reversed.": "The reaction is started by"'"heating the magnesium strongly in a bunsen flame."''"The magnesium oxide formed has quite different properties to either the magnesium metal or the oxygen."''"A new compound is formed.": 5o$="true ":t$="true ":e$="correct ":150 |\"The separation of sand from"'"water by filtration is a"'"physical method of separation": K"Water passes through the filter paper, but particles of sand"'"do not": ;"Sand and water together form a mixture."''"No new chemical substances are formed when this mixture is"'"separated. The water and the"'"sand were present both before and after the filtration."''"A change which does not involve the creation of new chemical"'"substances is classified as a physical change.": "This describes what happens"'"when the mixture of sand and"'"water is filtered."''"The liquid which passes through the filter paper is called the filtrate."''"The solid which remains in the filter paper is called the"'"residue.": D!1:5500|:0:"because"'"no new chemical substances are formed."''"The statement that"':1:5550:0:'"describes how the filter paper works, but does not explain why separation by filtration is"'"classified as a physical"'"separation technique.": v5o$="true ":t$="true ":e$="not correct":150 pC"Water is a mixture of hydrogen and oxygen and not a compound": K"Water can be split up by"'"electrolysis to give hydrogen and oxygen": J"Water is a compound of hydrogen and oxygen."''"Water can be formed by burning hydrogen in oxygen - a chemical change. A lot of energy is"'"released, and a new substance isformed."''"2H + O 2H O 2 2 2"''"The proportions of hydrogen and oxygen combined together are in a fixed ratio.": "When two electrodes are placed in water, and an electric"'"current is passed, hydrogen and oxygen are formed."''"A small amount of sulphuric acidis normally added to increase the electrical conductivity."''"Two volumes of hydrogen are"'"formed for every one volume of oxygen." i j*o$="false":t$="true ":e$="":150 dQ"The properties of iron sulphide are different from those of ironand sulphur": U"Iron and sulphur combine in"'"fixed proportions by mass to"'"form iron sulphide": 1"With dilute hydrochloric acid:"''"Iron sulphide gives hydrogen"'"sulphide gas (rotten egg smell);iron gives odourless hydrogen; sulphur has no reaction."'''"Iron is magnetic;"'"sulphur dissolves in some"'"organic solvents;"'"iron sulphide shows neither of these properties.": "All pure samples of the same"'"chemical compound contain the same elements combined in fixed proportions by mass."''"This is because elements consistof atoms which combine together in a fixed ratio when compounds are formed.": ,"A compound and its constituent elements are different chemical substances."''"Different chemical substances"'"have diffent chemical"'"properties.": ^5o$="true ":t$="true ":e$="not correct":150 Xa"An element is a substance which cannot be split into simpler"'"substances by chemical means": X"An element is made of"'"indivisible and indestructible particles called molecules": "This is a definition of the term""element""."''"""chemical means"" is stated so that radioactive decay and the atom-smashing methods of nuclearphysics are excluded.": k"Although some elements normally exist as molecules, the majoritydo not."''"Molecules can be broken up to give atoms, so they are not"'"indivisible."''"The atomic theory suggests that:"''"1 all matter is made of atoms; 2 atoms cannot be created or"'" destroyed (by chemical means);3 all atoms of a given element are (chemically) identical.": Q R*o$="true ":t$="false":e$="":150 La"A compound cannot be separated into simpler substances by"'"physical separation techniques": ~N"A compound consists of two or more elements chemically bonded together": "Physical separation techniques include:"''" filtration"'" distillation"'" chromatography"''"These methods can only be"'"used to separate mixtures of"'"substances."''"They cannot break down compoundsinto their constituent elements.": "This is the definition of a"'"compound."''"When elements are chemically"'"bonded together, they can only be separated by chemical"'"processes."''"Chemical reactions can break thebonds between atoms."'"Physical processes cannot do"'"this.": F5o$="true ":t$="true ":e$="correct ":150 @W"Liquefied air can be separated into oxygen and nitrogen by"'"simple distillation": rG"Liquid oxygen and liquid"'"nitrogen have different boiling points": C"Liquid air is separated into"'"oxygen and nitrogen by"'"fractional distillation."''"Simple distillation is used to separate a liquid from non-"'"volatile solids."''"To separate liquids with similarboiling points, the repeated"'"condensation and re-evaporation which occurs in a fractionating column is necessary.": "Liquid oxygen boils at -183 and liquid nitrogen at -196 degrees Celsius."''"The small difference in boiling points allows the two liquids tobe separated by fractional"'"distillation."''"The liquid nitrogen has the"'"lower boiling point, and so"'"distils off first.": :*o$="false":t$="true ":e$="":150 !4T"The coloured substances found ingrass can be separated by paper chromatography": !fa"The distance moved by a"'"substance on chromatography"'"paper is determined by its"'"colour": !"Grass is ground up with a"'"liquid to extract the pigments (coloured substances)."''"A spot of the solution obtained is placed near the bottom of thechromatography paper." !21004: !"The chromatogram is developed byallowing a solvent to rise up the paper by capillary action."''"A number of green and yellow"'"spots rise to different"'"positions. Each spot is a"'"different coloured compound.": !%"The distance moved by a compoundon chromatography paper is"'"determined by:"''"1 its solubility in the solvent;2 how strongly it is absorbed by the paper."''"Very soluble, weakly absorbed substances move furthest."''"Insoluble, strongly absorbed"'"substances do not move at all." !21004::"There is no simple relationship between colour and solubility, or between colour and extent of absorption."''"Therefore the colour of a"'"compound cannot determine the distance that it travels on the chromatography paper.": ".*o$="true ":t$="false":e$="":150 s5  B 22aScL$chem2 T4 3V4  J J WARREN 1982 s=0:c(10 ) %n=110 :c(n)=0:n ('b$=" " 2i:g=13:s$:m=07:a:s$+m,a:m:g:l$="" 7"a",0,0,0,255,255,0,0,0,"b",0,0,0,127,127,0,0,0,"c",0,24,12 ,254,254,12 ,24,0 <n=1:s=0 P-:5:6;7;" ";0;" Educational Software " UK12 ,0;" Structure, Bonding and Properties." Z17,0;6;"  1982 J J Warren BSc ARCS Cert Ed " x21004:7: }"Do you want:";5,3;"1. A revision tutorial"''" 2. A simple test"''" 3. A copy of the questions"'" on your printer?";19,0;"Type 1, 2 or 3." ""130 =""132 m$= mm$="3"''''" Structure, Bonding and Properties."''"________________________________"'''' !m$="1"m$="2"m$="3"140 130 3750+500*n  r$="" m$="4"c(n)=18204 *"Question ";n''"First Statement"'' 3500 +500*n +8,0;"Second statement"'' 3550 +500*n m$="3":8204 219,0;"Is the first statement true?" 1000 f$="true " i$="n" f$="false" 719,0;"Is the second statement true?" " 1000 6 s$="true " @i$="n"s$="false" O19,0;b$ T"f$"true "s$"true "420 ^Z18,0;"Is the 2nd statement a correct explanation of the 1st? " | 1000 r$="correct " i$="n"r$="not correct"  m$="2"810* %f$=o$"Well done, you were right." f$o$"You were wrong." 'l$ 76:" The first statement was ";o$;" ":7 l$'' $o$="true "3500 +500*n  x=0  2000  's$=t$"Good, your answer was right." &!s$t$"Your answer was wrong." :'l$ D76:" The second statement was ";t$;" ":7 Nl$'' b$t$="true "3550 +500*n l x=1 v 2000 { e$=""800   x=2 %r$""r$e$"You were wrong. "''l$ $r$=e$"Good, you were right."''l$ e$"correct "740 S"Both statements are true, and the 2nd is a correct explanationof the 1st."'l$' 3500 +500*n '"because"'' 3550 +500*n  21004  800  '" The fact that "'' 3550 +500*n "'" is not the reason why "''  3500 +500*n  2000   *!f$=o$s$=t$r$=e$c(n)=1 4 n=n+1 >n<11 140 ?m$="3"m$="4"960 @n=110 B s=s+c(n) Dn Ha("Excellent."s=10 )+("Very good."s=9 )+("Well done."s=8)+("Good."s=7) pDs=5s=6"You need to spend more time on this topic." zOs<5"Your very low score indicates a poor understanding of this topic" :'"You correctly answered ";s;" out"'"of 10 questions."'' is<5"You need to read through your notes and text-book again,"'"and then re-run this program." 21004: m$="1"s=10 960 K"Do you want to go through the questions in which you made"'"mistakes?"  1000 i$="n"960 m$="4"  n=1  140  *"Do you want to run the program again?"  1000   i$="n"  10 621,0;"Type y or n. " ""1015 =""1020 i$= i$="y"i$="n" ,21,0;" Please type y n." $ 1015 V "Well done, you were right.": "No, You were wrong.": T20,0;"Type e for explanation/comment otherwise press the ENTER key." ""2010 =""2020 =13 "e"2010 :l$ Nx=0o$="true "x=1t$="true "3500 +500*n+502*x  l$'' #3600+500*n+502*x  21004 * 4621,0;"Press the ENTER key to continue." >""2110> H=""2120H M13 21004 R 7"All atoms of carbon have the"'"same atomic number": ."All atoms of carbon have the"'"same mass": "The atomic number is equal to"'"the number of protons in the"'"nucleus of the atom."''"It is also equal to the number of electrons around the nucleus of the neutral atom.":21004:  "Each element has its own atomic number."''"All carbon atoms have 6 protons in the nucleus and 6 electrons outside it."''"Therefore all carbon atoms"'"have an atomic number of 6.": 6"Atoms of different isotopes of an element have different"'"masses."''"Although all carbon atoms have 6 protons, they can have"'"different numbers of neutrons.":21004: ;["Most carbon atoms have 6 protonsand 6 neutrons in the nucleus (6+6 gives a mass number of 12).These are atoms of the isotope carbon-12."''"Some carbon atoms contain"'"6 protons and 8 neutrons"'"(6+8 gives a mass number of 14).These are atoms of the isotope carbon-14."''"This means that carbon atoms canhave different masses.": *o$="true ":t$="false":e$="":150 M"The sodium ion and the neon atomhave the same electron"'"configurations": A"The sodium ion and the neon atomhave the same atomic number": "Sodium configuration: 2,8,1"''"Neon configuration: 2,8"''"Sodium easily loses its one"'"outer shell electron to give a configuration of 2,8 - the same as that of neon."''15;"+ -"'" Na Na + e"''" 2,8,1 2,8 1": *"Two different elements cannot have the same atomic number."''"The atomic number of neon is 10,and that of sodium is 11.": *o$="true ":t$="false":e$="":150 ?"The magnesium atom forms an ion with two positive charges": 4"Magnesium is in Group 2A of the periodic table": "The magnesium atom has 12"'"protons in the nucleus, and 12 extra-nuclear electrons."''"Its electron configuration is 2,8,2"''"The two outer shell electrons are easily given up."''"This results in the formation of an ion with two positive"'"charges." $21004::" 2+ -"'" Mg Mg + 2e"'" 2,8,2 2,8 2 "''''"The magnesium ion still has"'"12 protons in the nucleus, but it only has 10 electrons."''''" charge on protons +12"'" charge on electrons -10"''" overall charge +2": N"Magnesium is in Group 2A of the Periodic Table because it has similar physical and chemical properties to the other elementsin the group."''"The Group 2A elements are:"''"  Be beryllium "'"  Mg magnesium "'"  Ca calcium "'"  Sr strontium "'"  Ba barium "'"  Ra radium ": P("The magnesium atom forms an ion with two positive charges"'"as a consequence of"'"its atomic structure and"'"electron configuration."'''"The Periodic Table is simply a list of the elements arranged in a special way."''"A list cannot explain why an"'"ion has two positive charges.": 5o$="true ":t$="true ":e$="not correct":150 |4"The nitrogen atom can form threecovalent bonds": B"The nitrogen atom has only threeelectrons in the outer shell": 6"Nitrogen has the electron"'"configuration 2,5."''"If it gains a share in three"'"more electrons, it will have a configuration like that of neon (2,8)."'"It can do this by forming three covalent bonds, as in the"'"ammonia molecule:"'20;"H"'20;"|"'18;"H-N:"'20;"|"'20;"H": {"Nitrogen is in Group 5B of the Periodic Table, It has 5 outer shell electrons."'''"Nitrogen configuration: 2,5": v*o$="true ":t$="false":e$="":150 p4"Oxygen can form both ionic and covalent bonds": 8"Oxygen is a gas at room"'"temperature and pressure": Կ"Oxygen (2,6) can get a rare gas electron configuration by:"'''"(1) Gaining two electrons to"'"form the oxide ion as in"'"magnesium oxide."''"(2) Forming two covalent bonds as in water.": "Oxygen consists of small,"'"diatomic molecules:"''," O"'," 2"''"The forces of attraction betweenthese molecules are very weak."''"As a result, oxygen is a gas at room temperature and pressure.": 8"Oxygen is a gas at rtp,but this cannot explain why oxygen forms both ionic and covalent bonds."'''"Oxygen forms both ionic and"'"covalent bonds"''" because"''"its atoms can attain more stableelectron configurations by"'"either gaining or sharing"'"electrons.": j5o$="true ":t$="true ":e$="not correct":150 d6"The chloride ion has a single negative charge.": \"The chlorine atom easily loses one electron to give a rare gas electron configuration": ȫ"The Halogens (fluorine,"'"chlorine, bromine and iodine) all form ions with a single"'"negative charge."'''" - - - -"'" F Cl Br I": "Chlorine (2,8,7) gains one"'"electron giving a configuration like that of argon(2,8,8)."'''" - -"'" Cl + e Cl"''"2,8,7 1 2,8,8": ^*o$="true ":t$="false":e$="":150 X1"Solid sodium chloride conducts electricity": L"Sodium chloride is an ionic"'"solid at room temperature and pressure": >"There are no common solid"'"compounds which conduct"'"electricity."''"This is because solid compounds do not contain mobile charge"'"carriers."''"However, sodium chloride does conduct electricity when melted or dissolved in water."''"This is because its ions are"'"then free to move and carry"'"charge.": "Solid sodium chloride consists of sodium ions and chloride ionsheld together by electrostatic attraction."''"The regular arrangement of ions is called an ionic crystal"'"lattice.": R*o$="false":t$="true ":e$="":150 L1"Graphite is a non-conductor of electricity": ~D"The only solid elements which"'"conduct electricity are metals": f"In graphite the carbon atoms arecovalently bonded together in sheets."''"Each carbon atom uses three"'"electrons to form normal"'"covalent bonds to its neighbours"''"The forth outer shell electron of each carbon atom is free to move and carry an electric"'"current - it is delocalised."''"Therefore graphite is a"'"conductor of electricity.": ["All metallic elements contain mobile electrons which act as charge carriers."''"Graphite is a form of the non- metal carbon."''"Although graphite has a giant covalent lattice structure, it does have mobile electrons. It is a fairly good conductor of electricity."''"So at least one non-metallic"'"element conducts electricity.": F*o$="false":t$="false":e$="":150 @."Iodine dissolves well in organicsolvents": rW"The iodine atom has one less"'"outer shell electron than the"'"following rare gas": "Iodine exists as small covalent molecules (I )."'12 ;"2"''"Such substances usually dissolvewell in organic solvents."''"The iodine molecules are attrac-ted to the solvent molecules by van der Waals forces, and so theiodine dissolves.": ֛"Iodine is an element in Group 7Bof the Periodic Table."''"It has seven outer shell"'"electrons - one less than the rare gas xenon, which has eight.": I"Although both statements are"'"true, there is no simple"'"connection between them."'''"Iodine dissolves well in organicsolvents"'"because"'"the inter-molecular attractions between the iodine molecules andthe solvent molecules can over- come the weak forces which hold the iodine molecules together inthe iodine crystal.": :5o$="true ":t$="true ":e$="not correct":150 !4-"All non-metals have low melting points.": !fK"The covalent bonds between the atoms of non-metals are rather weak": !_"Non-metals which exist as small molecules do have low melting points (e.g. nitrogen and"'"chlorine)."''"However, non-metals with giant covalent lattice structures havevery high melting points"'"(e.g. carbon and silicon)."''"Melting points/degrees Celsius:"'"nitrogen -210"'"chlorine -101"'"carbon 3727 (sublimes)"'"silicon 1410": ! "Covalent bonds are strong bonds."''"The chlorine molecule consists of two atoms strongly held"'"together by a covalent bond."''"However, as there are only weak van der Waals forces between themolecules, chlorine is a gas at room temperature and pressure.": ".*o$="false":t$="false":e$="":150 s 22a5 B ScL$chem3 4 3(4  J J WARREN 1982 s=0:c(10 ) %n=110 :c(n)=0:n ('b$=" " <n=1:s=0 P-:5:6;7;" ";0;" Educational Software " UN12 ,0;" Redox, Electrolysis and the"'" Activity series." Z17,0;6;"  1982 J J Warren BSc ARCS Cert Ed " d@:g=15:s$:m=07:a:s$+m,a:m:g nl"a",0,0,0,255,255,0,0,0,"b",0,0,0,127,127,0,0,0,"c",0,24,12 ,254,254,12 ,24,0,"d",0,0,0,60<,4,60<,32 ,60<,"e",0,0,0,60<,4,28,4,60< s+l$="" x21004:7: }"Do you want:";5,3;"1. A revision tutorial"''" 2. A simple test"''" 3. A copy of the questions"'" on your printer?";19,0;"Type 1, 2 or 3." ""130 =""132 m$= qm$="3"''''" Redox, Electrolysis and the"'" Activity Series."''"________________________________"'''' !m$="1"m$="2"m$="3"140 130 3750+500*n  r$="" m$="4"c(n)=18204 *"Question ";n''"First Statement"'' 3500 +500*n +8,0;"Second statement"'' 3550 +500*n m$="3":8204 219,0;"Is the first statement true?" 1000 f$="true " i$="n" f$="false" 719,0;"Is the second statement true?" " 1000 6 s$="true " @i$="n"s$="false" O19,0;b$ T"f$"true "s$"true "420 ^Z18,0;"Is the 2nd statement a correct explanation of the 1st? " | 1000 r$="correct " i$="n"r$="not correct"  m$="2"810* f$=o$"Well done." f$o$"Wrong." 'l$ 76:" The first statement was ";o$;" ":7 l$'' $o$="true "3500 +500*n  x=0  2000  s$=t$"Well done." &s$t$"Wrong." :'l$ D76:" The second statement was ";t$;" ":7 Nl$'' b$t$="true "3550 +500*n l x=1 v 2000 { e$=""800   x=2 %r$""r$e$"You were wrong. "''l$ $r$=e$"Good, you were right."''l$ e$"correct "740 S"Both statements are true, and the 2nd is a correct explanationof the 1st."'l$' 3500 +500*n '"because"'' 3550 +500*n  21004  800  '" The fact that "'' 3550 +500*n "'" is not the reason why "''  3500 +500*n  2000   *!f$=o$s$=t$r$=e$c(n)=1 4 n=n+1 >n<11 140 ?m$="3"m$="4"960 @n=110 B s=s+c(n) Dn Ha("Excellent."s=10 )+("Very good."s=9 )+("Well done."s=8)+("Good."s=7) pDs=5s=6"You need to spend more time on this topic." zOs<5"Your very low score indicates a poor understanding of this topic" :'"You correctly answered ";s;" out"'"of 10 questions."'' is<5"You need to read through your notes and text-book again,"'"and then re-run this program." 21004: m$="1"s=10 960 K"Do you want to go through the questions in which you made"'"mistakes?"  1000 i$="n"960 m$="4"  n=1  140  *"Do you want to run the program again?"  1000   i$="n"  10 621,0;"Type y or n. " ""1015 =""1020 i$= i$="y"i$="n" ,21,0;" Please type y n." $ 1015 V "Well done, you were right.": "No, You were wrong.": T20,0;"Type e for explanation/comment otherwise press the ENTER key." ""2010 =""2020 =13 "e"2010 :l$ Nx=0o$="true "x=1t$="true "3500 +500*n+502*x  l$'' #3600+500*n+502*x  21004 * 4621,0;"Press the ENTER key to continue." >""2110> H=""2120H M13 21004 R 2"Elemental chlorine oxidises"'"iron (II) ions": A"Chlorine molecules can take"'"electrons from iron (II) ions": +"Oxidation is the process by"'"which atoms, molecules or ions lose electrons."''"When an iron (II) ion loses one electron, an iron (III) ion is formed."''" 2+ 3+ -"'" Fe Fe + e"''"The electrons are taken by the chlorine, which acts as an"'"oxidising agent.": 612 ;"- -"'" Cl + 2e 2Cl"'" 2"'"  ^ "''"These electrons are taken from iron (II) ions."''"The chlorine molecules are"'"reduced to chloride ions.": 5o$="true ":t$="true ":e$="correct ":150 J"Metals high in the activity"'"series have good reducing"'"properties": R"Reduction is the process by"'"which atoms, molecules or ions gain electrons": >"A reducing agent gives electronsto the substance which is being reduced."''"Metals high in the activity"'"series, such as potassium,"'"readily give up electrons, and"'"form positive ions."''"They therefore act as reducing agents, and are themselves"'"oxidised."'" + -"'"e.g. K K + e": *B"This is the modern definition ofreduction. For example, when"'"potassium is burnt in oxygen, the oxygen gains electrons and is therefore reduced."'11 ;"- 2-"'" O + 4e 2O"'" 2"''"The electrons come from the"'"potassium, which is oxidised."'" + -"'" 4K 4K + 4e": \"The metals which are readily"'"oxidised (have good reducing"'"properties) are placed at the top of the activity series."''"This is simply the way in which chemists have agreed to arrange the activity series.": 5o$="true ":t$="true ":e$="not correct":150 ["The conversion of sulphite ions to sulphate ions is neither"'"oxidation nor reduction": R"The charge on the sulphite ion is the same as the charge on thesulphate ion": J"The conversion of sulphite ions to sulphate ions is oxidation. The partial ionic equation is:"''" 2- 2- + -"'"SO + H O SO +2H + 2e"'" 3 2 4"''"The sulphite ions give up"'"electrons and gain oxygen."''"Oxidation is electron loss."''"Oxidation is the gain of oxygen.": t"Both ions have a double negativecharge:"'''" 2-"," 2-"'" SO","SO"'" 3"," 4"''"sulphite sulphate": *o$="false":t$="true ":e$="":150 |R"The change from ethene (CH=CH)to ethane (CHCH) is classifiedas reduction": `"Reduction can be defined as a process involving the addition of hydrogen to a substance": "Addition of hydrogen has taken place, therefore the change is reduction."''"CH =CH + H CH CH"'" 2 2 2 3 3"''"The reaction takes place when ethene gas and hydrogen are"'"passed over a heated nickel"'"catalyst.": t"Other definitions include:"''"Reduction is the loss of oxygen"''"Reduction is the gain of"'"electrons.": v5o$="true ":t$="true ":e$="correct ":150 pU"When copper (II) oxide is heatedin a stream of hydrogen, copper metal is formed": +"Copper (II) oxide is a reducing agent": "The black copper oxide is"'"reduced to a reddish-brown"'"powder. This is a very fine formof copper metal."''"The hydrogen is oxidised to"'"water."''" CuO + H Cu + H O"'" 2 2": "CuO + H Cu + H O"'" 2 2"''"Copper (II) oxide is reduced to copper metal, and the hydrogen is oxidised to water."''"The copper (II) oxide has acted as an oxidising agent in this reaction": j*o$="true ":t$="false":e$="":150 dN"When zinc reacts with iodine to form zinc iodide, the iodine is oxidised": R"The change from molecular iodineto iodide ions involves the gainof electrons": "When zinc reacts with iodine to form zinc iodide,"''"The zinc is oxidised (loses"'"electrons)"'" 2+ -"'" Zn Zn + 2e"''"The iodine is reduced (gains"'"electrons)"'" - -"'" I + 2e 2I"'" 2" Җ21004::"The overall equation for the"'"reaction is:"''" Zn + I ZnI"'" 2 2"''"Zinc iodide is an ionic"'"compound.": '" - -"'" I + 2e 2I"'" 2"''"In the reaction between iodine and zinc, the iodine molecules gain electrons from the zinc"'"atoms, and are reduced to iodideions.": ^*o$="false":t$="true ":e$="":150 XR"Silver metal reacts with dilute hydrochloric acid to liberate hydrogen gas": I"Silver is above hydrogen in the activity (electrochemical)"'"series": "Silver is too unreactive a metalto liberate hydrogen gas from acids."''"It will dissolve in oxidising acids, e.g. in nitric acid, but no hydrogen is formed.": "Potassium  The activity series Sodium  lists the metals in Lithium  order of decreasing Calcium  reactivity. Magnesium  Aluminium  Copper and silver Zinc  are both below Iron  hydrogen in the Lead  activity series. Hydrogen  Neither can liberateCopper  hydrogen from acids.Silver ": R*o$="false":t$="false":e$="":150 LC"Zinc metal will displace copper from copper sulphate solution": ~3"Zinc is below copper in the"'"activity series": "Zinc is the more reactive metal,and is oxidised to give"'"zinc (II) ions."''" 2+ -"'" Zn Zn + 2e"''"The electrons from the zinc"'"reduce the copper (II) ions to copper metal."''" 2+ -"'" Cu + 2e Cu": "Zinc is above copper in the"'"activity series."''" Potassium "'" Sodium "'" Lithium "'" Calcium "'" Magnesium "'" Aluminium "'" Zinc "'" Iron "'" Lead "'" Hydrogen "'" Copper "'" Silver " 21004::"Metals higher in the activity"'"series can displace metals lowerin the series from solutions of their salts."''"For example:"''" 2+ 2+"'"Zn(s)+ Cu (aq) Zn (aq)+ Cu(s)": "The activity series is based on the relative reactivities of themetals."''"One of the reasons for zinc"'"being above copper in the"'"activity series is the fact thatzinc will displace copper from aqueous solutions of its salts.": F*o$="true ":t$="false":e$="":150 @]"When molten lead bromide is"'"electrolysed, a brown vapour"'"comes off from the cathode": r@"During electrolysis reduction takes place at the cathode": 6"Bromine is formed at the anode when molten lead bromide is"'"electrolysed. The bromine can beseen as a brown vapour."''"The molten electrolyte contains lead ions and bromide ions."''"The anions (negative bromide"'"ions) are attracted to the anodeand lose electrons. They undergoelectrolytic oxidation." I'" - -"'" 2Br Br + 2e"'" 2": "Positively charged ions(cations)are attracted to the cathode."''"They gain electrons from the"'"cathode, and so are reduced."''"For example, lead ions gain"'"electrons to form lead atoms."''" 2+ -"'" Pb + 2e Pb": :*o$="false":t$="true ":e$="":150 !4{"When copper sulphate solution iselectrolysed using graphite"'"electrodes, hydroxide ions are discharged at the anode": !fm"Hydroxide ions have a single"'"negative charge, whereas"'"sulphate ions have a double"'"negative charge": !G"The anions present are hydroxideions (from the ionisation of"'"water) and sulphate ions."'"The hydroxide ions are"'"discharged to give oxygen gas:"''" - -"'"4OH O + 2H O + 4e"'" 2 2"''"Some carbon dioxide is formed due to oxidation of the graphiteanode by the oxygen.": !^" -"," 2-"'" OH","SO"'," 4"''"Hydroxide Sulphate"' " ion ion": !z"Although the hydroxide ion has avery much lower concentration than the sulphate ion in copper sulphate solution, The hydroxideions are selectively discharged."''"However, there are examples in which ions with higher charges are discharged in preference to ions with a lower charge."''"There is no simple reason why some ions are discharged in"'"preference to others.": ".5o$="true ":t$="true ":e$="not correct":150 s dda<5 B SeL$Xchem4 4 3G4  J J WARREN 1982 s=0:c(10 ) %n=110 :c(n)=0:n ('b$=" " 2i:g=15:s$:m=07:a:s$+m,a:m:g:l$="" 7q"a",0,0,0,255,255,0,0,0,"b",0,0,0,127,127,0,0,0,"c",0,24,12 ,254,254,12 ,24,0,"d",0,0,63?,0,63?,63?,24,12 ,"e",16,8,252,0,252,252,0,0 <n=1:s=0 P-:5:6;7;" ";0;" Educational Software " U112 ,4;"Acids, Bases and Salts." Z17,0;6;"  1982 J J Warren BSc ARCS Cert Ed " x21004:7: }"Do you want:";5,3;"1. A revision tutorial"''" 2. A simple test"''" 3. A copy of the questions"'" on your printer?";19,0;"Type 1, 2 or 3." ""130 =""132 m$= Rm$="3"''''" Acids, Bases and Salts."''"________________________________"'''' !m$="1"m$="2"m$="3"140 130 3750+500*n  r$="" m$="4"c(n)=18204 *"Question ";n''"First Statement"'' 3500 +500*n +8,0;"Second statement"'' 3550 +500*n m$="3":8204 219,0;"Is the first statement true?" 1000 f$="true " i$="n" f$="false" 719,0;"Is the second statement true?" " 1000 6 s$="true " @i$="n"s$="false" O19,0;b$ T"f$"true "s$"true "420 ^Z18,0;"Is the 2nd statement a correct explanation of the 1st? " | 1000 r$="correct " i$="n"r$="not correct"  m$="2"810* %f$=o$"Well done, you were right." !f$o$"Your answer was wrong." 'l$ 76:" The first statement was ";o$;" ":7 l$'' $o$="true "3500 +500*n  x=0  2000  )s$=t$"Good, your answer was correct." &s$t$"You were wrong." :'l$ D76:" The second statement was ";t$;" ":7 Nl$'' b$t$="true "3550 +500*n l x=1 v 2000 { e$=""800   x=2 2r$""r$e$"Unfortunately you were wrong."''l$ $r$=e$"Good, you were right."''l$ e$"correct "740 S"Both statements are true, and the 2nd is a correct explanationof the 1st."'l$' 3500 +500*n '"because"'' 3550 +500*n  21004  800  '" The fact that "'' 3550 +500*n "'" is not the reason why "''  3500 +500*n  2000   *!f$=o$s$=t$r$=e$c(n)=1 4 n=n+1 >n<11 140 ?m$="3"m$="4"960 @n=110 B s=s+c(n) Dn Ha("Excellent."s=10 )+("Very good."s=9 )+("Well done."s=8)+("Good."s=7) pDs=5s=6"You need to spend more time on this topic." zOs<5"Your very low score indicates a poor understanding of this topic" :'"You correctly answered ";s;" out"'"of 10 questions."'' is<5"You need to read through your notes and text-book again,"'"and then re-run this program." 21004: m$="1"s=10 960 K"Do you want to go through the questions in which you made"'"mistakes?"  1000 i$="n"960 m$="4"  n=1  140  *"Do you want to run the program again?"  1000   i$="n"  10 621,0;"Type y or n. " ""1015 =""1020 i$= i$="y"i$="n" ,21,0;" Please type y n." $ 1015 V "Well done, you were right.": "No, You were wrong.": T20,0;"Type e for explanation/comment otherwise press the ENTER key." ""2010 =""2020 =13 "e"2010 :l$ Nx=0o$="true "x=1t$="true "3500 +500*n+502*x  l$'' #3600+500*n+502*x  21004 * 4621,0;"Press the ENTER key to continue." >""2110> H=""2120H M13 21004 R "All acids contain oxygen": H"All acids may be formed by"'"dissolving non-metal oxides in water": "The majority of acids do containoxygen, e.g."''" HNO H CO H SO"'" 3 2 3 2 4"''"A few acids do not contain"'"oxygen. Hydrochloric acid, HCl, is one example.": 6<"Many acids are formed when non- metal oxides are dissolved in water."'"E.g., sulphur trioxide dissolves to give sulphuric acid:"''" H O + SO H SO"'" 2 3 2 4"''"However, it is not true of all acids."''"Hydrochloric acid is made by"'"dissolving hydrogen chloride"'"gas (HCl) in water.": h"You cannot give a reason for a definition or commonly accepted term."''"Scientists have simply agreed to use the term in that way so that they can understand each other.": *o$="false":t$="false":e$="":150 C"Acids react with sodium"'"carbonate giving a colourless"'"gas": <"Acids contain hydrogen which maybe replaced by a metal": "The colourless gas is carbon dioxide."''"  Acid + Metal Carbonate"''"  gives "''"Salt + Carbon Dioxide + Water "''"This reaction is characteristic of acids.": *"This is sometimes used as the"'"definition of an acid."''"An acid is a proton (hydrogen"'"ion) donor, and so must contain hydrogen."''"When an acid reacts with a base the hydrogen ions are replaced by metal ions (or other cations such as the ammonium ion) to"'"give a salt.": \"The colourless gas formed when acids react with sodium"'"carbonate is carbon dioxide."''"For example, if the acid is"'"hydrochloric acid, then:"''"Na CO + 2HCl 2NaCl + CO + H O 2 3 2 2": 5o$="true ":t$="true ":e$="not correct":150 D"A solution of sulphur dioxide in water turns red litmus blue": B"Sulphur dioxide dissolves in"'"water to form sulphurous acid": "Sulphur dioxide is an acidic"'"oxide."''"It dissolves in water to give sulphurous acid."'''" Acids turn blue litmus red.": '" H O + SO H SO"'" 2 2 2 3"''"The sulphurous acid ionises to give hydrogen and sulphite ions:"'',"+ 2-"'" H SO 2H + SO"'" 2 3 3"''"The hydrogen ions make the"'"solution acidic.": *o$="false":t$="true ":e$="":150 |A"Ethanoic (acetic) acid in"'"aqueous solution is a weak acid": @"Ethanoic acid dissolves in waterto give a solution of pH 7": "A weak acid is one which is onlypartly ionised."''"In water, most of the ethanoic acid is present as molecules."'"Only a small proportion is"'"ionised."''," - +"'" CH CO H CH CO + H"'" 3 2 3 2": "pH 7 corresponds to a neutral solution."''"Acids in aqueous solution give apH of less than 7."''''"The pH of dilute ethanoic acid solution is about 3."''"(The exact value depends upon the concentration).": v*o$="true ":t$="false":e$="":150 p*"Hydrochloric acid is a strong acid": N"Hydrochloric acid is formed by dissolving hydrogen chloride gasin water": "A strong acid is highly ionised,and so gives a high"'"concentration of hydrogen ions."''"Hydrochloric acid consists of hydrogen ions and chloride ions in aqueous solution."'',"+ -"'" HCl H + Cl"  21004::"The solution of hydrogen"'"chloride in water is more fully"'"represented by:"'''," + -"'"HCl(g)+H O(l)H O (aq)+Cl (aq) 2 3"'''" +"'"H O is the hydrated hydrogen 3 ion. It is called the hydronium ion.": "Hydrogen chloride is very"'"soluble in water."''"When it dissolves the molecules split up to form ions. The ions are hydrated.":21004::"The hydrogen ions (protons) are bonded to water molecules"'"forming hydronium ions:"''''" H + The oxygen atom of ^ the water molecule H-O uses a lone pair of | electrons to form a H dative bond to the hydrogen ion.": 8"There is no direct connection between solubility and the"'"strength of an acid."''"Sulphur dioxide is very soluble in water. Sulphurous acid is"'"formed, but this is a rather"'"weak acid.": j5o$="true ":t$="true ":e$="not correct":150 dK"When ammonia gas is dissolved inwater it forms an alkaline"'"solution": 8"Ammonia reacts with water to"'"form hydroxide ions": Ȫ"Ammonia is a base and so gives asolution with a pH greater than 7."''"Ammonia solution turns red"'"litmus blue, thus showing that the solution is alkaline.": "Ammonia acts as a base by"'"accepting a hydrogen ion from a water molecule."''"This yields ammonium and"'"hydroxide ions:"''," + -"'"NH + H O NH + OH 3 2 4"''"The hydroxide ions make the"'"solution alkaline.": ^5o$="true ":t$="true ":e$="correct ":150 XY"Black copper oxide dissolves in dilute sulphuric acid to form a colourless solution": @"Metal sulphates always give"'"colourless aqueous solutions": "Black copper oxide does dissolvein dilute sulphuric acid, but"'"the solution formed is blue."'''"The products of the reaction arecopper sulphate(blue) and water."'''"H SO + CuO CuSO + H O 2 4 4 2"''"Acid + Base Salt + Water": ,"The colour of solutions of metalsulphates depends on the colour of the metal ion, as the"'"sulphate ion is colourless."''"The majority of common metal"'"ions are colourless in solution.Exceptions include:"''" Copper (2+) Blue"'" Iron (2+) Pale green"'" Iron (3+) Brownish-yellow": R*o$="false":t$="false":e$="":150 L5"Carbon dioxide is classified as an acidic oxide": ~+"Carbon dioxide turns lime-water milky": ""Carbon dioxide dissolves in"'"water giving carbonic acid:"''" H O + CO H CO "'" 2 2 2 3"''"Carbon dioxide also reacts with and neutralises bases, for"'"example, with sodium hydroxide solution:"''" CO + 2NaOH Na CO + H O 2 2 3 2": "Lime-water is a saturated"'"solution of calcium hydroxide."''"This reacts with carbon dioxide to give calcium carbonate."''"Ca(OH) + CO CaCO + H O 2 2 3 2"''"The calcium carbonate formed is insoluble in water, and forms a milky-white suspension.": "Carbon dioxide is classified as an acidic oxide because it will react with and neutralise bases."''"The reaction with lime-water is just one example of this"'"behaviour."''"Note that other acidic oxides may react with lime-water, but they do not turn it milky." : F5o$="true ":t$="true ":e$="not correct":150 @1"Potassium hydrogensulphate is a normal salt": r}"Potassium hydrogensulphate is formed when equal numbers of"'"moles of potassium hydroxide andsulphuric acid are mixed": 1"A normal salt is formed when allof the hydrogens of an acid arereplaced by metal ions."''"Potassium hydrogensulphate is"'"an acid salt."'''" H SO KHSO K SO"'" 2 4 4 2 4"''" Acid Acid Normal salt  salt ": "H SO + KOH  KHSO + H O "'" 2 4 4 2"''"When one mole of potassium"'"hydroxide reacts with one mole of sulphuric acid, only one of the hydrogens of the acid is"'"replaced by potassium ions.": :*o$="false":t$="true ":e$="":150 !4b"Lead iodide can be prepared by mixing cold solutions of lead nitrate and potassium iodide": !f/"Lead iodide is quite soluble in hot water": !"When the two colourless"'"solutions are mixed, bright"'"yellow crystals of lead iodide are formed."''"Pb(NO ) + 2KI PbI + 2KNO 3 2 2 3"''"The precipitated lead iodide canbe separated from the potassium nitrate solution by filtration.": !"Lead iodide is almost insoluble in cold water, but does dissolvein hot water to give a"'"colourless solution."''"When this solution is cooled, the lead iodide crystallises outas glittering yellow crystals.": !"Lead iodide can be prepared by mixing cold solutions of lead nitrate and potassium iodide because it is insoluble in cold water, and not because it is"'"soluble in hot water.": ".5o$="true ":t$="true ":e$="not correct":150 s 22a5 B SeL$