chemistry

1 inwhich pair do the atoms contain the same number of neutrons?
a "band ?c
b ‘liand °be
cc mg and “si
d “nand °o

2 two hydrocarbons have the formulae cwhx and cyhz. w, x, y and z represent different whole
numbers.
www.y
x z.
which row is correct when comparing the two hydrocarbons?
empirical molecular relative
formula formula molecular mass
a different same different
b different same same
c same different different
d same different same

3. ‘the airbags in cars contain sodium azide, nan3, and an excess of potassium nitrate, kno3.
in a car accident, the reactions shown occur, producing nitrogen. this causes the airbag to inflate
rapidly.
2nan3 > 2na + 3n2

10na + 2kno3 + k20 + 5na2o + no
how many moles of nitrogen gas are produced in total when 1mol of sodium azide, nansz,
decomposes in an airbag?
a 1.5 b 1.6 c 3.2 d 4.0

4 ethane burns in oxygen to produce carbon dioxide and water vapour.
which bond angles are present in the molecules of ethane and its combustion products?
[| ettane [combustion rues
a 90° 104.5° and 180°
b 90° 109.5° and 120°
cc 109.5° 104.5° and 180°
d 109.5° 109.5° and 180°

5 asample of an ideal gas is contained at a constant temperature of 300k in a gas syringe.
the pressure is increased and a graph of a against pressure is plotted.
which graph correctly represents the results?
a
b
pv
rt cc
d
p

6 in calculating the enthalpy cnange, ah, of an experiment involving solutions, the mass of the
solution, m, specific heat capacity of the solution, c, and the temperature change, at, are
needed.

at = tiinat — tinitiat
which expression for ah is correct?
a ah= me b ah=—™2 © ah=mcat d_= ah=-mcat
at at

7 the following data are needed for this question.

ah? (p4oi0(s)) = -3012kj mol

ah® (h2o(1)) = -286 kj mol

ah? (h3po,(s)) = -1279 kj mol
what is ah® for the reaction shown?

p4o10(s) + 6h2o(i) + 4h3po,(s)

a -9844kj mol"
b -388kj mol’
c -97kjmol"
d +2019kjmol"

8 which statement is always correct for an oxidation reaction?
a_ it involves the gain of oxygen by an element.
b_ for one reactant to be oxidised a different reactant must be reduced.
c_ the element or ion being oxidised will gain electrons.
d_ the oxidation number of the element being oxidised will increase.

9 nitrogen dioxide, noz, is a brown gas.
dinitrogen tetroxide, n2ou,, is a colourless gas.
an equilibrium is established between no, and n20, in a closed vessel.
2no2(g) == n20,(g) ah =-57kj mol"
brown colourless
which row describes the effects of changing conditions on the colour of an equilibrium mixture of
noz and n204?
[| nerasing te pressure | ineasing he temperate |
a colour becomes darker colour becomes darker
b colour becomes darker colour becomes lighter
cc colour becomes lighter colour becomes darker
d colour becomes lighter colour becomes lighter

10 a large excess of marble chips was reacted with 25 cm* of 1.0 moldm™ hydrochloric acid at 40°c.
how will the result be different when the reaction is repeated with 60 cm® of 0.5moldm™?
hydrochloric acid at 40°c?

a_ the reaction is faster and less of the products are made.
b_ the reaction is faster and more of the products are made.
c_ the reaction is slower and less of the products are made.
d_ the reaction is slower and more of the products are made.

11° which change alters the activation energy of a given reaction?
a_ adding a suitable catalyst
b_ changing the particle size of the reactants
c_ changing the pressure at which the reaction is carried out
d_ changing the temperature at which the reaction is carried out

12 the relative magnitude of the property x of five elements is shown. p, q, r, s and t are all in
period 3 and have consecutive atomic numbers.
r
q
p
xx
ss if
atomic number
which row shows a correct pairing of property x and element r?
a electrical conductivity al
b electronegativity si
cc melting point al
d | second ionisation energy si

13 element z has a giant structure.
the chloride of z reacts with water to give a solution with a ph less than 5.
which row shows two elements which could be z?
a aluminium, magnesium
b aluminium, silicon
c_ phosphorus, magnesium
d phosphorus, silicon

14 radium is an element below barium in group 2 of the periodic table.
which equation shows what happens when solid radium nitrate, ra(no3)2, is heated strongly?
a ra(nos)2(s) > rao(s) + n2o(g) + 202(g)
b  2ra(no3)(s) > 2rao(s) + 2n2(g) + 502(g)
c 2ra(nos)(s) > 2rao(s) + 4no.(g) + o2(g)
d 4ra(nos3)(s) > 2ra20(s) + 8no.(g) + 302(g)

15 exactly 3.705kg of substance y are needed to neutralise 100 moles of hc/(aq).
what could be substance y?
a ca b cao c ca(oh) d caco;

16 in an experiment, 0.125 mol of chlorine gas, cl2, is reacted with an excess of cold, aqueous
sodium hydroxide. one of the products is a compound of sodium, oxygen and chlorine.
which mass of this product is formed?
a 9.31g b 13.3g c 18.6g d 26.6g

17 sodium bromide reacts with concentrated sulfuric acid.
which observation will be made?
a acoloured vapour is produced.
ba purple solid is formed.
c_ astrong smell of h2s is detected.
d_ yellow sulfur is formed.

18 the reaction of nitrogen and oxygen to produce oxides of nitrogen happens at high temperatures
in car engines or lightning strikes during thunderstorms.
what is the main reason for these reactions requiring such high temperatures?
a _ the lack of reactivity of nitrogen, due to the half-filled 2p subshell in the nitrogen atom
b _ the lack of reactivity of nitrogen, due to the strength of the bond in nz
c the lack of reactivity of oxygen, due to electron-electron repulsion in one of its 2p orbitals
d the lack of reactivity of oxygen, due to the strength of the bond in o2

19 xis a mixture of two compounds of group 2 elements.
x undergoes thermal decomposition to produce a white solid and only two gaseous products.
one of the gaseous products relights a glowing splint.
what could be the components of mixture x?
a mgclz and caco;
b  mgcos3 and ca(nos)2
c mg(nos)2 and ca(no3)2
d mgo and cao

20 which compound does not exhibit stereoisomerism?
a  ch3chcich2cho
b  ch3;chchch;
c ch,cich2cci2h
d chcichci

21 the diagram shows the skeletal formula of citric acid.
[@) oh
sta
ho ‘oh
oh
citric acid
what is the molecular formula of citric acid?
a cohs07 b  cehs07 c cghgo7 d  ciohgo7

22 which compound would produce two different carboxylic acids when treated with hot,
concentrated, acidified manganate(vij) ions?
a b cc d

23 which types of bond are broken and formed in the addition polymerisation of alkenes?
bond broken bond formed
a mt only o only
b nm only oandz
cc oandz o only
d oandx oandx

24 2,3-dimethylpent-2-ene, (ch3)2c=c(ch3)ch2chs, is treated with cold, dilute kmno,. the product
of this reaction is treated with an excess of concentrated h2so, at 180°c, giving a mixture of
isomeric hydrocarbons with molecular formula c7h,2.

what is the name of one of the isomeric hydrocarbons?
a 2,3-dimethylpenta-1,2-diene
b_cis-2,3-dimethylpenta-1 ,3-diene

c  2,3-dimethylpenta-1,4-diene

d_ 3,4-dimethylpenta-1,3-diene

25 equal volumes of aqueous silver nitrate were added to separate small volumes of bromoethane
and iodoethane in two test-tubes. the test-tubes were shaken.
which row about the observations made for bromoethane is correct?
a cream faster than for iodoethane
b cream slower than for iodoethane
cc yellow faster than for iodoethane
d yellow slower than for iodoethane

26 many, but not all, organic reactions need to be heated before a reaction occurs.
which reaction occurs quickly at room temperature (20 °c)?
a ch30h + pcls — ch3cl + poci3 + hcl
b  ch;ch,br + kcn — ch3;ch2cn + kbr
c ch3ch20h — c2h, + h20
d ch3ch2cn + 2h20 — ch3ch2co2h + nhs

27 when compound x is warmed with dilute, acidified potassium dichromate(vi) there is no colour
change. x does not give an orange precipitate with 2,4-dinitrophenylhydrazine reagent.
what could x be?
a _ butan-2-ol
b_ethanal
c_ methylpropan-2-ol
d_propanone

28 what are the only structures formed when butan-2-ol is heated with concentrated h2so,4?
ch,ch, h ch, h
ae a j
a c=c c=c

~f * y, *

h h h ch,

ch, ch, ch, h h h
\ # \ \‘ #

c=c c=c c=c

ff * f/ * f

h h h ch, ch,ch, h

h h h h
% #7 \.. ff
f/ /  \

ch,ch, h ch, ch,

ch, h ch,ch, h h h

‘. \ \ 7
c=c c=c c=c

f f * f \

ch, h h h ch, ch,

29 compound g

e has achiral centre,
e gives a positive result with alkaline aqueous iodine,
e does not give a silver mirror with tollens’ reagent.

what could compound g be?

a 1-hydroxybutan-2-one

b 2-hydroxybutanal

c  3-hydroxybutanal

d  3-hydroxybutan-2-one

30 anester with an odour of banana has the following formula.
ch3;co,ch,chch;ch;
be
which pair of reactants, under suitable conditions, will produce this ester?
a ch3;ch,chch2co,h + ch3;0h
be
b  ch3;ch,chco2h + ch3;ch2oh
be
c ch3;cojh + ch3ch;chch,oh
be
d ch;co,h + ch;chch,ch,oh
an

31 in 2011 an international group of scientists agreed to add two new elements to the periodic
table. both elements had been made artificially and are called flerovium, fl, and livermorium, lv.
ee ee
proton number 114 116
nucleon number 289 292
from the information about atoms in the table, which statements are correct?
1 one atom of lv has one more neutron than one atom of fl.
2 one fi” ion has the same number of electrons as one atom of lv.
3 one lv‘ ion has the same number of electrons as one fi ion.

32 the chlorine oxide free radical, clos, is produced by the reaction between chlorine atoms and
ozone.
cle + o3 > clo* + o2
which features are present in the chlorine oxide free radical?
1 anodd number of electrons
2. asingle covalent bond
3 adative covalent bond from oxygen to chlorine

33 hydrogen sulfide can be oxidised to form sulfur dioxide.
2h2s + 302 > 2so,2 + 2h,0
which statements are correct?
1. the oxidation number of sulfur increases by 6.
2 the oxidation number of oxygen increases by 2.
3. the oxidation number of hydrogen decreases.

34 methanoic acid, hco2h, and hydrocyanic acid, hcn, can both behave as acids.
a solution of methanoic acid has a lower ph than a solution of hydrocyanic acid of the same
concentration.
which statements explain this?
1 hco;h molecules dissociate more fully than hcn molecules do.
2 each hco;h molecule has two hydrogen atoms; each hcn molecule only has one.
3. methanoic acid is a weaker acid than hydrocyanic acid.

35 which statements correctly describe a trend on going down group 2?
1 reactivity of the elements increases.
2 first ionisation energy of the elements decreases.
3 the hydroxides become more soluble in water.

36 modern cars are fitted with catalytic converters to reduce atmospheric pollution caused by
unwanted reactions during the combustion of the fuel.
which statements are correct?
1. carbon monoxide is oxidised to carbon dioxide in a catalytic converter.
2 catalytic converters have a very large surface area.
3. nitrogen dioxide is reduced to nitrogen monoxide in a catalytic converter.

37 which statements are correct for an sy2 mechanism?
1 one bond is being broken at the same time as another bond is being formed.
2 the formation of the intermediate involves the collision of two molecules or ions.
3. acarbon atom in the transition state is bonded, either fully or partially, to five atoms.

38 bromoethane is heated under reflux with concentrated aqueous naoh.
which statements are correct?
1. the major product is a primary alcohol.
2 the major reaction is hydrolysis by an sy2 mechanism.
3 the major product would be the same if the naoh is dissolved in ethanol.

39 compound m is an important ingredient in perfume.
oo
on
compound m
m reacts with hcn.
which statements about this reaction are correct?
1. asmall amount of naoh will speed up the reaction.
2 the reaction is initiated by the transfer of a proton to one of the c=o groups.
3 both of the c=o groups react with hcn.

40 carboxylic acids can be converted into their salts by a number of reactions at room temperature.
which reactions would produce sodium butanoate and a gas?
1 sodium carbonate + butanoic acid
2 sodium + butanoic acid
3. sodium hydroxide + butanoic acid

Solve 9701_w17_qp_12