0620 Chemistry Theory

Question 1

Answer 1

carbon dioxide

Question 2

Answer 2

78%

Question 3

Answer 3

calcium oxide

Question 4

Answer 4

catalytic converter

Question 5

Answer 5

(i) CH4
(ii) lowest relative molecular mass

Question 6

Answer 6

It is toxic.
It causes suffocation.

Question 7

Answer 7

M1 glucose
M2 oxygen

Question 8

Answer 8

M1 two dot-and-cross double bonds

M2 two pairs of non-bonding electrons on O and zero non-bonding electrons on C

Question 9

Answer 9

metallic

Question 10

Answer 10

lighted splint and (squeaky) pop

Question 11

Answer 11

ph14

Question 12

Answer 12

universal indicator

Question 13

Answer 13

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

M1 NaOH as product in equation (1)

M2 fully correct equation (1)

M3 state symbols (1)

Question 14

Answer 14

isotope(s)

Question 15

Answer 15

Question 16

Answer 16

M1(6x10)+(7x90)(=690)
M2 690 / 100 = 6.9 (1)

Question 17

Answer 17

M1 eight dots in third shell of both K (1)

M2 six crosses and two dots in second shell of O (1)

M3 ‘+’ charge on each K on correct answer line and ‘2–‘ charge on O ion on correct answer line (1)

Question 18

Answer 18

nitrogen: air (1)
hydrogen: methane (1)

Question 19

Answer 19

enthalpy change

Question 20

Answer 20

(the value of) ΔH is negative

Question 21

Answer 21

M1 450 (1)
M2 20 000 (1)
M3 iron (1)

Question 22

Answer 22

Question 23

Answer 23

M1 kinetic energy of particles increases (1)
M2 frequency of collisions between particles increases (1)
M3 particles have energy greater than to activation energy (1)

Question 24

Answer 24

(i) H2SO4
(ii) fertiliser
(iii) M1 Mr of (NH4)2SO4 = 132 (1)
2 X 14 = 28
and
%N = 100 X 28 / 132 = 21.2% (1)

Question 25

Answer 25

(i) zinc (ii) alloy

Question 26

Answer 26

(i) ductility (ii) electrons

Question 27

Answer 27

(i) high melting point (ii) (act as) catalysts

Question 28

Answer 28

(i) water(s) of crystallisation (ii) blue (iii) CuSO4∙5H2O

Question 29

Answer 29

(i) basic (ii) the oxidation number of copper is +2 (iii) M1 Mr of Cu(NO3)2 = 188 (1) M2=0.0200x M1=0.0200 x188=3.76 g (1) (iv) M1 moles of gas formed = 0.0200  5 / 2 = 0.05(00) (1) M2 volume = M1  24.0 = 0.05(00)  24.0 = 1.2(0) (1)

Question 30

Answer 30

2Al + 3CuO → Al2O3 + 3Cu

Question 31

Answer 31

(a) same functional group (b) carboxylic acids (c) CnH2n+1COOH (d) propan-2-ol (1)

Question 32

Answer 32

(i) C10H22 → C3H8 + C3H6 + C4H8 (ii) cracking

Question 33

Answer 33

(i) sodium propanoate (ii) CH3CH2COO–

Question 34

Answer 34

(i) any named inorganic acid, e.g. phosphoric acid (ii) ethyl propanoate