chemistry

1. which statement about the avogadro constant is correct?
a _itis the mass of one mole of any element.
b_itis the mass of 6.02 x 107° atoms of any element.
c_itis the number of atoms in one mole of neon.
d it is the number of atoms in 12g of any element.

2 which equation represents the first ionisation energy of iodine?
a 71g) + & > tg)
b ig) + e& > ig)
cc 719) > vg) + &
d ig) > tg) te

3 the structures represent three compounds, each with four carbon atoms per molecule.
xx y z
oo oo o
aa, a pp ue
which row is correct?
lowest highest
boiling point boiling point

a xx ¥ z
b ¥ xx zz
cc z x y
d z x x

4 the structural formula of alliin is shown.
alliin
h h oo nh,
| ty | /z|
x ee i
h co,h
what are the approximate bond angles x, y and z in a molecule of alliin?
pf x | oy fe
a 90° 90° 109°
b 120° 109° 90°
cc 120° 120° 109°
d 180° 109° 109°

5 flask q contains 5dm° of helium at 12kpa pressure. flask r contains 10dm” of neon at 6kpa
pressure.
if the flasks are connected at constant temperature, what is the final pressure?
a 8kpa b 9kpa c 10kpa d 11kpa

6 sodium cnioride, water and air represent three states of matter — solid, liquid and gas.
which row is correct?
a particles held can easily be can easily be
in rigid structure compressed compressed
b particles stationary particles move cannot easily be
compressed
cc particles stationary particles stationary particles move
d resistant to cannot easily be can easily be
change of shape compressed compressed

7 the reaction pathway diagram for the catalysed reaction and the uncatalysed reaction between
no and hz is shown.
n2(g) + 3h2(g) = 2nh,(g)
which letter represents the activation energy for the first step in the decomposition of nh3 in the
presence of a catalyst?
a
b
energy y |.
n,(g) + 3h,(g) d
eee 2nh,(g)
reaction pathway

8 nitrogen and oxygen can react together to form nitrogen monoxide, no.
nz + o2 > 2no ah = +180kj mol
what is the bond energy of the bond between the atoms in no?
a 630kjmol’ b 810kjmol' c 1260kjmol' d = 1620kjmot™

9 the equation for a redox reaction is shown.
sncl2(aq) + 2hgcl2(aq) > sncl4(aq) + hg2cl2(s)
which species is being oxidised in this reaction?
a sn” b cr c hg" d hg**

10 3.60 moles of hydrogen gas and 2.00 moles of lodine vapour are placed in a reaction vessel
which is then sealed and maintained at a constant temperature.
the equation for the reaction is shown.
h, + i, = 2hi
at equilibrium, 3.20 moles of hydrogen remain. all reactants and products are gaseous.
what is the value of k, under these conditions?
a 0.0313 b 0.125 c 0.156 d_ 8.00

11. two chemicals, x and y, react together in solution to give product z.
the rate of formation of product z at the start of the reaction was measured in five experiments,
1—5, using various concentrations of x and y. the results are shown.
number of x/moldm* of y/moldm-* at the start/moldm™*s“*

1 0.10 0.10 0.0001
2 0.10 0.20 0.0004
3 0.10 0.40 0.0016
4 0.20 0.10 0.0001
5 0.40 0.10 0.0001

which statement is correct?

a_ the rate of the reaction is directly proportional to the concentration of reagent x.

b_ the rate of the reaction is directly proportional to the concentration of reagent y.

c_ the rate of the reaction is not affected by the concentration of reagent x.

d_ the rate of the reaction is not affected by the concentration of reagent y.

12 asample of sicl, is added to cold water.
which statement describes the mixture formed at the end of the reaction?
a acidic solution with no precipitate
b acidic solution with white precipitate
c neutral solution with no precipitate
d neutral solution with white precipitate

13 land m are elements in period 3 of the periodic table.
e the oxide of l is a solid at room temperature. this oxide has a giant structure.
e the chloride of l does not react with water.
e argon is the only element in period 3 with a lower melting point than m.
which formula represents a compound of elements l and m?
a al2s3 b mgs c nacl d pcls

14 a farmer requires a solid compound to raise the ph of the soil in a field from 5.5 to above 6.0.
which compound could the farmer use?
a (nh4)2so,4 b  nh,no; c ca(oh) d = ca(no3)2

15 z is an anhydrous compound of a group 2 element. when it is heated, z undergoes thermal
decomposition to produce two different gases. z has relatively low thermal stability compared to
other group 2 compounds containing the same anion as z.

what is compound z?

a barium carbonate

b _ barium nitrate

c magnesium carbonate
d magnesium nitrate

16 which row gives mixtures that both result in the oxidation of a halide ion?
[were
a agno;(aq) and nacl(aq) concentrated h2so,(aq) and hi(aq)
b br2(aq) and nacl(aq) concentrated h2so.(aq) and hcl(aq)
cc cl2(aq) and nabr(aq) ch3chbrch,(i) + naoh (ethanolic)
d br2(aq) and nali(aq) concentrated h2so,(aq) and nabr(s)

1/ chiorine gas is widely used to treat contaminated water.
when chlorine is added to water, which chemical species present is responsible for killing
bacteria?
a clo. b cl cc hcl d clo”

18 what is an environmental consequence of the uncontrolled use of nitrate fertilisers?
a acid rain
b low oxygen levels in streams
c_ ozone depletion
d_ the greenhouse effect

19 ammonia gas, nh3, and hydrogen sulfide gas, h2s, react together to form the salt ammonium
sulfide, (nh4)2s. ammonium sulfide dissolves in water to produce an orange alkaline solution.
(nh,)2s(aq) == nh3(aq) + nh,sh(aq)

the addition of naoqh(aq) to this solution produces a gas, x.
the addition of hcl(aq) to a separate portion of this solution produces a gas, y.
x and y could represent different gases or identical gases.
what are the identities of x and y?
| | x | yf
a h2s h2s
b h2s nh3
cc nh3 h2s
d nh3 nh3

20 compound p is treated with an excess of hydrogen gas in the presence of a nickel catalyst. the
product q is fully saturated.
compound p
~% .
what is the number of chiral carbon atoms in the product q?
a 4 b 5 cc 6 d7

21 hexadeca-10,12-dien-1-ol is produced by silk moths from hexadecanoic acid in a three-step
enzymic process.
hexadecanoic acid
oo
aaa ee
step 1
nr ek
step 2
pn no
| step 3
ns ne nee oh
which row contains correct descriptions of the three steps?
[set [see [ae
a elimination elimination dehydration
b elimination reduction reduction
cc oxidation elimination oxidation
d oxidation oxidation reduction

22 compound x can be converted into compound y in a single step.
compound y
yy
o o
what could be the identity of x?
a b cc d

23 methane and bromine react by free radical substitution.
p and q are involved in the reaction mechanism.
p and q:
e are both involved in propagation steps as reactants
e are both involved in termination steps as reactants.
what could be p and q?
a brandh b- brand ch; c brand ch, d  ch3 and ch3br

24 a few drops of 2-bromopropane were placed in a test-tube. an equal volume of aqueous
silver nitrate was added. a precipitate was formed.
the experiment was repeated with 2-iodopropane.
which row is correct?
colour of precipitate from faster rate of reaction
2-bromopropane + agno;(aq)

a cream 2-bromopropane + agno:;(aq)

b yellow 2-bromopropane + agno:;(aq)

cc cream 2-iodopropane + agno;(aq)

d yellow 2-iodopropane + agno;(aq)

25 sodium methoxide, na*ch3;0°, reacts with 2-chloro-2-methylpropane in a nucleophilic
substitution reaction. the nucleophile is the ch3o07 ion.
which row is correct?
intermediate or
oe ee
a (chs3)3c* (ch3)3cochs
b (chs3)3c* (ch3)3cch2oh
h;c ch, |
c | an ae | hoch2c(chs)3
bu
h;c ch; |
d | a 2 | h3coc(chs)s
bu

26 alcohol x reacts with concentrated sulfuric acid to produce a mixture of products.
two of the products are structural isomers of each other.
what could be x?
a_hexan-2-ol
b_pentan-1-ol
c _pentan-3-ol
d_propan-2-ol

27 which reaction will form a strong organic base?
a ethanol and acidified sodium dichromate
b_ ethanol and hot aluminium oxide
c_ ethanol and sodium
d_ ethanol and hydrogen chloride

28 which reaction mechanism for the formation of c2hsch(oh)(cn) is correct?
ht
m oe oh
0. oh a
a oy a —_—_> —>
( cc c
n=c: _,
h | |
n n
ht
™ of j oh
\ e hh 4
b yy é — é
n==c; ~—
h | |
n n
ht
- o: = oh
o. bn i
(e \ e> — é —> é
n==c:_%
h | |
n n
ht
x o; = oh
\ é eh hh
d ef —. és —_— se
n=cc; went
h | |
n n

29 the synthesis shown may be used for the production of propan-1-ol.
step 1 step 2
-_s sp 1 compound x bier fey
n
which row gives the correct reagents for steps 1 and 2?
[ [set see |
a hcl(aq) h2 + ni
b hcl(aq) lialh,
cc naoh(aq) h2 + ni
d naoh(aq) nabh,

30 the molecular formula of z is c4hgo.
the infra-red spectrum of z is shown.
100
transmittance /%
50
0
4000 3000 2000 1500 1000 500
wavenumber/cm
what could be z?
a b cc d
oh (@)
7 png
— oh os™ oy

31. in which ions are the number of electrons equal to the number of neutrons?
1 ‘sf
2 oe
3 na*

32 compound x is a straight chain hydrocarbon with an m, of 84.
what can be determined about x?
1. empirical formula
2 ~~ molecular formula
3. whether x contains a c=c bond or not

33. when a sample of ammonium chloride is warmed it decomposes into ammonia and hydrogen
chloride gas.
nh,cl(s) — nhs(g) + hcl(g) reaction 1
nar suc i ammonium
chloride (reformed)
f ammonium chloride
heat
when the mixture of hot ammonia and hydrogen chloride gases hit a cold surface, a white solid of
ammonium chloride reforms.
which statements are correct?
1. reaction 1 is in dynamic equilibrium.
2 reaction 1 is reversible.
3 reaction 1 is an endothermic reaction.

34 hydrogen chloride gas is formed by the reaction shown.
h2(g) + cla(g) > 2hci(g)
what will change the average kinetic energy of the reacting gas particles?
1 increasing the temperature and increasing the concentration of hydrogen
2 cooling the reaction mixture and adding a catalyst
3. adding a catalyst and increasing the concentration of chlorine

35 which oxides will cause a change in ph when added to water?
1 cao
2  alzo03
3 sio,

36 which reaction routes can be used to make a pure sample of barium sulfate?
4 ba heat eoduict dilute radiict dilute eeduet filter, wash
ino, ° hor p heo, * and dry
strong solid an excess dilute filter, wash
2  ba(no,), ——————> —— duct ———» duct ————>
a(no3) feat in air” product of water prouuc h,so, freee and dry
dilute dilute filter, wash
3. ba(oh), ————> duct ———> duct. ———_—_>
ah: png, peta eg preduel didn

37 cortisone is a synthetic hormone.
cortisone
fe) oh
ho oh
h
(@)

which classes of alcohol does this molecule contain?
1 primary alcohol
2 secondary alcohol
3 tertiary alcohol

38 which changes are commonly involved in the formation of an addition polymer?
1 the formation of a o-bond
2 the breaking of a n-bond
3 the change in hybridisation of the orbitals of a carbon atom from sp* to sp*

39 which alcohols can be oxidised to form an organic compound which will give coloured
precipitates with both 2,4-dinitrophenylhydrazine reagent and alkaline aqueous iodine?
oh
cy
oh o
2 on
3 on

40 which mixtures form a carboxylic acid as one of the products?
o
1 pra + h,so,(aq) >
o-
2 ak, + h,so,(aq) >
3 anas + h,80,(aq) >

Solve 9701_s21_qp_12