,                                                                                                              ,                           Fractional distillation is used 
         ts                                                                                                             ts
                                                                                GCSE AQA Revision • Chemistry                                       to separate components 
                     es                                                                                                            es               with different 
                                    Explain how fractional                                                                                                                     boiling points 
                     tur            distillation can be used to                                                                    tur              from a mixture. The mixture 
         , Elemen    x                                                                                                  , Elemen   x
                     i              separate a mixture.                                                                            i                is heated gradually and each 
                     M                                                                                                             M
         oms   ompounds and                                                                                             oms   ompounds and          component is collected when 
         t     C                                                                                                        t     C                     it boils.
         A                                                                                                              A
                                                                                                    1                                                                                                              1
                                                                                GCSE AQA Revision • Chemistry                                       Each isotope of an element 
                  able              If an element has different                                                                  able               has the same number of 
                                    isotopes, what does this                                                                                        protons but a different 
           oms and the              mean?                                                                                 oms and the               number of neutrons in 
           t      eriodic T                                                                                               t      eriodic T          each atom.
           A      P                                                                                                       A      P
                                                                                                    2                                                                                                              2
                                    Complete the gaps                                                                                               The centre of the 
                                                                                                                                                                                      Periodic 
                                    in the sentences.                                                                                               Table between Groups 2 and 
           able                     The centre of the                           GCSE AQA Revision • Chemistry             able                      3 contains elements known as 
           T                        Periodic Table                                                                        T                         the transition metals.
                                    between Groups 2 and 3 contains                                                                                 Atoms of these elements 
                                    elements known as the … … .                                                                                     form ions with different 
                                    Atoms of these elements form …                                                                                  charges.
           eriodic                  with different charges.                                                               eriodic                   The compounds formed by 
                                    The compounds formed by these                                                                                   these elements are coloured.
           he P                     elements are … .                                                                      he P                      They can be used as catalysts 
           T                        They can be used as … to                                        3                     T                         to speed up chemical                                           3
                                    speed up chemical reactions.                                                                                    reactions.
           tter                     Complete the table.                         GCSE AQA Revision • Chemistry             tter                       State of substance State symbol
                                                                                                                                                     solid                                  (s)
                                      State of substance State symbol                                                                                liquid                                 (l)
                                      solid                                  ( … )                                                                   gas                                    (g)
           es of Ma                   …                                      (l)                                          es of Ma                   (aqueous)                              (aq)
           t                          …                                      (g)                                          t                          dissolved in water
           Sta                        ( … ) dissolved                        ( … )                                        Sta
                                      in water                                                      4                                                                                                              4
                                    Describe what                               GCSE AQA Revision • Chemistry                                       The metal atoms lose electrons to 
                                    happens to a metal atom and                                                                                     become positively charged ions. 
                                    a non-metal atom when an                                                                                        The electrons are transferred to 
           ompounds                 ionic bond forms between                                                              ompounds                  the non-metal atoms, which gain 
                                    them.                                                                                                           electrons to become negatively 
           Ionic C                                                                                                        Ionic C                   charged ions.
                                                                                                    5                                                                                                              5
                                                GCSE AQA Revision • Chemistry 
                      What properties of metals                                          Metals contain metallic 
                      make them useful structural                                        bonds, which are very strong. 
       Metals         materials?                                         Metals          Most metals have high 
                                                                                         melting and boiling points.
                                                            6                                                                  6
                                                GCSE AQA Revision • Chemistry 
                      Describe what happens when                                         An electron from each atom 
                                     atom forms a                                        is shared so that each atom 
       ompounds       one chlorine                                       ompounds
       t C            bond with another chlorine                         t C             has a complete outer shell of 
       alen           atom.                                              alen            electrons.
       v                                                                 v
       o                                                    7            o                                                     7
       C                                                                 C
                                                                                         The atoms within polymer 
                                                GCSE AQA Revision • Chemistry            molecules are held together 
       terials        Explain why most                                   terials         by strong covalent bonds. 
                      polymers are solid at room                                         The intermolecular forces 
                      temperature.                                                       between the large polymer 
                                                                                         molecules are also quite 
       Special Ma                                                        Special Ma      strong.
                                                            8                                                                  8
                                                GCSE AQA Revision • Chemistry 
                      Why do chemical symbol                                             Mass is conserved. In a chemical 
       tion of Mass   equations always need to be                        tion of Mass    reaction, no atoms are made 
       a              balanced?                                          a               or lost.
       v                                                                 v
       onser                                                9            onser                                                 9
       C                                                                 C
       e              Which of the                                       e
                      following sentences 
                      are true and which        GCSE AQA Revision • Chemistry                                               23
                      are false?                                                         A is true: one mole is 6.02 × 10  
                                                                                                                   23
                      A.  Three moles of potassium                                       atoms, so 3 × 6.02 × 10  = 
                          atoms contain a total of just                                             23
                  HT                    23                                           HT  18.06 × 10  atoms
                          over 18 × 10  atoms
       t of Substanc  B.  Sodium has a lower relative atomic             t of Substanc   B is false: one mole of any element 
                         mass than potassium, so three                                                                23
                         moles of sodium atoms                                           always contains 6.02 × 10  atoms
       moun              contain fewer than                10            moun                                                 10
       A                          23                                     A
                         18 × 10  atoms
                                                                                GCSE AQA Revision • Chemistry                                       Concentration
                                    What is the                                                                                                                 = amount of substance
                                                                                   3                                                                                             volume
           tion                     concentration of 0.5 dm                                                               tion
           a                  HT    solution containing 1.5 moles                                                         a                  HT                     1.5 mol
           itr                                                                                                            itr                                   =                3
           T                        of hydrochloric acid?                                                                 T                                         0.5 dm
                                                                                                                                                                = 3 mol/dm3
                                                                                                  11                                                                                                              11
                                    The following 
           and   y                  reaction equations                                                                    and  y 
                                    show two different                          GCSE AQA Revision • Chemistry 
           ield                     ways in which we                                                                      ield                      Reaction B, because all the 
                 onom               can produce ethanol.                                                                       onom
                                    A. CH O                         2C H OH + 2CO                                                                   reactant atoms end up in the 
           tage Y                            6   12    6                2    5                   2                        tage Y                    desired product (ethanol).
                                    B. CH  + H O                          C H OH
                 om Ec                       2   4        2                  2   5                                             om Ec
           en    t                  Which reaction, A or B, has an atom                                                   en   t
           c     A                                                                                                        c    A
           r                        economy of 100%? How do                                                               r
           e                                                                                      12                      e                                                                                       12
           P                        you know this?                                                                        P
                                    Use these words 
                                    to complete the 
                                    sentences that                              GCSE AQA Revision • Chemistry                                       In oxidation reactions, a 
                                    follow. (Use each                                                                                               substance often gains oxygen.
                                    word once only.)
                                    together   loses   gains                                                                                        In reduction reactions, a 
                                    In oxidation reactions, a substance                                                                             substance often loses oxygen.
                                    often … oxygen.
           tivity of Metals         In reduction reactions, a substance                                                   tivity of Metals          Oxidation and reduction always 
                                    often … oxygen.                                                                                                 occur together.
           Reac                     Oxidation and reduction                                       13                      Reac                                                                                    13
                                    always occur … .
           alts                                                                                                           alts
                                    Why is the following  GCSE AQA Revision • Chemistry                                                             Hydrochloric acid (HCl) 
                                    reaction called a                                                                                               neutralises the alkali 
           ale and S                neutralisation reaction?                                                              ale and S                 potassium hydroxide (KOH). 
           c                                                                                                              c                         The solution that remains has 
                                    HCl(aq) + KOH(aq)                                                                                               a pH of 7, meaning that it is 
                                                                          KCl(aq) + H O(l)
                                                                                                2                                                   neutral.
           he pH S                                                                                14                      he pH S                                                                                 14
           T                                                                                                              T
           sis                                                                  GCSE AQA Revision • Chemistry             sis
           oly                      Explain why electrolysis is an                                                        oly                       Electrolysis requires a lot of 
           tr                       expensive way of extracting                                                           tr                        heat and electrical energy. 
                                    metals
           Elec                                   from their ores.                                                        Elec
                                                                                                  15                                                                                                              15
             tions                                                                                                          tions
                                                                                GCSE AQA Revision • Chemistry                                       Endothermic reactions take in 
                                    What is the difference                                                                                          energy from the surroundings 
                                    between endothermic and                                                                                         and cause a temperature drop. 
                                    exothermic reactions?                                                                                           Exothermic reactions give out 
        othermic and                                                                                                   othermic and                 energy to the surroundings and 
        Ex                                                                                                             Ex                           cause a temperature rise.
             Endothermic Reac                                                                     16                        Endothermic Reac                                                                      16
                                                                                                                                                    An endothermic reaction 
                                    If a reaction is                            GCSE AQA Revision • Chemistry                                       takes in energy from the 
           ells                     endothermic, what does this tell                                                      ells                      surroundings. This means 
                              HT    us about the energy needed to                                                                            HT     that the energy needed to 
           uel C                    break and make bonds in the                                                           uel C                     break bonds is greater than 
           F                        reaction?                                                                             F                         the energy given out by the 
                                                                                                                                                    making of bonds.
                                                                                                  17                                                                                                              17
                                    A sample of solid 
                                    calcium carbonate                                                                                               The half that is broken into 
           tion                     is divided precisely                        GCSE AQA Revision • Chemistry             tion                      small pieces will react faster. 
                                    into two equal                                                                                                  This is because small pieces 
                                    masses. One half is a single                                                                                    have a large surface area 
                                    solid piece, which is then                                                                                      in relation to their volume. 
                                    reacted with an acid. The                                                                                       More solid particles are 
                                    other half is broken into small                                                                                 exposed to contact with 
           te of Reac               pieces and reacted with a                                                             te of Reac                acid particles, so there are 
           a                        fresh sample of the same acid.                                                        a                         more collisions and a faster 
           R                        Which half will react faster,                                                         R                         reaction.
                                    and why?                                                      18                                                                                                              18
                                  Choose the correct phrase 
                                  from this list to complete                                                                                        When a reversible reaction 
           tions                  the sentence that follows.                    GCSE AQA Revision • Chemistry             tions                     takes place in a closed 
                                  much less than                                                                                                    system, an equilibrium is 
                                  exactly the same as
                                  much more than                                                                                                    achieved when the rate of the 
                                  When a reversible reaction takes place                                                                            backward reaction is exactly 
           ersible Reac           in a closed system, an equilibrium                                                      ersible Reac              the same as the rate of the 
           v                      is achieved when the rate of the                                                        v
                                  backward reaction is … the rate of                                                                                forward reaction.
           Re                     the forward reaction.                                           19                      Re                                                                                      19
                                    Choose the correct 
                                    general formula for                         GCSE AQA Revision • Chemistry 
                                    alkanes from the 
                                    following list.
                                    C H                                                                                                             C H
           kanes                       n   2n−2                                                                           kanes                       n   2n+2
           l                                                                                                              l
           A                        C H                                                                                   A
                                       2n    n
                                    C H
                                       n   2n
                                    C H                                                           20                                                                                                              20
                                       n   2n+2