chemistry

1 the boltzmann distribution is shown for a sample of gas at an initial temperature, 7;.
t,
proportion of
molecules with
energy, e
0
0 molecular energy, e
the sample of gas was heated to temperature, to.
what is the correct distribution for the higher temperature, 72?
qt,
proportion of
a molecules with
energy, e
0
0 molecular energy, e
proportion of t,
b molecules with
energy, e
0
q molecular energy, e
qt,
proportion of
cc molecules with
energy, e
0
9 molecular energy, e
qt,
proportion of
d molecules with
energy, e
0
9 molecular energy, e

2 a3.7g sample of copper(ii) carbonate is added to 25cm? of 2.0moldm~ hydrochloric acid.
which volume of gas is produced under room conditions?
a 0.60dm° b  0.72dm° c 1.20dm° d 2.40dm°

3. which statement about a 3p orbital is correct?
a itcan hold a maximum of 6 electrons.
b_ it has the highest energy of the orbitals with principal quantum number 3.
c_ itis at a higher energy level than a 3s orbital but has the same shape.
d_ it is occupied by one electron in an isolated phosphorus atom.

4 the eight species that follow all have covalent bonds.
in which pair do the species have different shapes from each other?
a becl, and co,
bch, and nh,*
cnhs and bf3
d sclz and h20

3 histidine is an amino acid.
histidine
h 2
h.-h
we tt p
h s a
no “co—c-—o—¢
\ f{ in n
c==n h oh o—h
/
h
what are the approximate bond angles 1, 2, and 3?
popo es
a 109.5 107 90
b 120 107 109.5
cc 120 120 90
d 120 120 109.5

6 asample of gas occupies 240 cm? at 37°c and 100kpa.
how many moles of gas are present in the sample?
a 932x10° b 9.32x10° cc 0.0781 d 78.1

7 p,qand r represent three different structures of an element.
p q r
wat
eo fe 8
| / | | \
! ; hy ; ‘ zuaers
\ i 1 | sf \ | bd
vy ! im 4 am,
an 4 <a
ec so
o_o
which structures are giant molecular?
a p,qandr
bp and q only
c_ pandr only
d qandronly

8 the standard enthalpy changes of combustion of carbon, hydrogen and methanol are shown.
c(s) + og) > co2(g) ah? = -394 kj mol
h2(g) + 402(g) > h20(i) ah? = —286 kj mol"
ch3oh(i) + 14.02(g) > co.(g) + 2h20() ah2= -726kj mol
which expression gives the standard enthalpy change of formation of methanol in kj mol"?
a ~-394 + (-286) — (—726)
b -394 + (-286 x 2) - 726
c -394 + (-286 x 2) — (-726)
d -726 — (-394) — (-286 x 2)

9 the equation for a chemical reaction is shown. all substances are in their standard states.
xefg + 3h20 > xeo3 + 6hf
which statement describes the standard enthalpy change of reaction for this reaction?
a the enthalpy change when a total of one mole of products is produced
b_ the enthalpy change when a total of one mole of reactants is reacted
c_ the enthalpy change when one mole of water reacts
d_ the enthalpy change when six moles of hydrogen fluoride are produced

10 acidified potassium manganate(vii) reacts with iron(ii) ethanedioate, fec2o,.
the reactions taking place are shown.
mno, + 8h* + 5e° — mn? + 4h,0
fe > fe* + @&
c20,7 > 2co2 + 2e7
how many moles of iron(ii) ethanedioate react with one mole of potassium manganate(vii)?
a 0.60 b 1.67 c 2.50 d 5.00

11. when copper is added to a solution of silver ions, the following equilibrium is established.
cu(s) + 2ag*(aq) == cu**(aq) + 2ag(s) k, = 1.0 x 108
what is the concentration of silver ions at equilibrium when [cu2"] = 0.10 mol dm °?
a 5.0 x 10’ moldm®
b 5.0 x 10“*moldm®
c 1.0 x 10 moldm?
d 1.0 x 10?moldm®

12 x, y and z are elements in period 3 of the periodic table. the results of some experiments
carried out with compounds of these elements are shown.
om | sss | seas | ss,
element the oxide of the the chloride of the the oxide of the
element to h2o(i) element to h20(i) element to hc1(aq)
xx no reaction hydrolyses forms chloride salt
e forms hydroxide dissolves forms chloride salt
z forms acid hydrolyses hydrolyses
which statement could be correct?
a xis aland y is mg.
b_~ xis si and y is na.
c yisaland zis p.
d yisnaandzisal.

13 asolid period 3 element, q, is reacted with oxygen gas. compound r is formed.
when r is added to water the ph decreases.
what could be the empirical formula of r?
a qo, b q,0; c qsoi9 d q;0,

14 metal t reacts with water to produce a colourless solution. a white precipitate is produced when
this colourless solution is mixed with aqueous sulfuric acid.
what is metal t?
a barium
b magnesium
c_ potassium
d_ sodium

15 when calcium nitrate thermally decomposes, oxygen is one of the products.
which volume of oxygen is produced under room conditions when 0.50 mol of calcium nitrate
thermally decomposes?
a 6.0dm° b  12.0dm° c 18.0dm° d 30.0dm°

16 l, m and n are group 2 metals. l reacts more vigorously with dilute hydrochloric acid than n
does. m(oh), is more soluble than n(oh),.
what could be the identities of l, m and n?
pp foe | mw |
a ba ca sr
b ba sr ca
cc ca ba sr
d sr ca ba

17 the table shows some reactions of a white compound, g.
followed by aqueous ammonia not dissolve when the ammonia is added
concentrated sulfuric acid including hydrogen sulfide
what could be the identity of g?
a_ caesium chloride
b lithium bromide
c potassium sulfate
d sodium iodide

18 under standard conditions, which statement is correct?
a cl,(aq) can oxidise br (aq).
b  cl,(aq) can reduce br (aq).
c cl (aq) can oxidise br2(aq).
d  cl(aq) can reduce br2(aq).

19 ammonia, nh3, and hydrazine, nh2nh2, are two compounds of nitrogen, no.
which statement is correct?
a the n-n bond in nh2nth? is polar.
b nh; and nh2nh;z have lone pairs of electrons but nz does not.
c_ the oxidation number of each nitrogen in nh2nk;% is +2.
d_ the reaction of nitrogen with hydrogen has a high activation energy.

20 how many structural isomers are there of trichloropropane, c3h;c13?
a 3 b 4 cc 5 d 6

21 compound l has the molecular formula c1ohi6.

a sample of l reacted with an excess of hot, concentrated, acidified potassium manganate(vii).

compound m is produced.

m
(e)
o
oh
[e)
what could be the structure of compound l?
a b cc d

22 many reactions take place in the engine and catalytic converter of a car.
which pair of substances is produced both by the reactions in a car engine and in a catalytic
converter?
a carbon dioxide and unburnt hydrocarbons
b_ carbon dioxide and water
c carbon monoxide and nitrogen
d_ carbon monoxide and unburnt hydrocarbons

23 structural isomerism and stereoisomerism should be considered when answering this question.
2-bromopentane is heated with an excess of ethanolic sodium hydroxide.
how many different hydrocarbons are produced?
a 1 b 2 cc 3 d 4

24 bromopropane reacts with water as shown.
ch3ch2ch2br + h20 — ch3ch2ch20h + hbr
which statement is correct?
a this is an elimination reaction.
b_ this is a hydrolysis reaction.
c_ this is a redox reaction.
d_ this reaction tends to proceed via the sy1 mechanism.

25 which product is formed when 3-methylpentane-1,3,4-triol is heated under reflux with an excess
of acidified potassium dichromate(vi)?
a  ho2cch2c(ch3)(oh)coch3
b ho,cch,coc(oh)(chs3)2
c ohcch2c(ch3)(oh)cochs
d ho2cch2co(ch3)coch3

26 menthol is a naturally occurring alcohol.
menthol
oh
when menthol is heated with concentrated sulfuric acid it reacts. the products formed include
compound t.
what could be the structure of compound t?
a b cc d
. “oo .

27 structural isomerism only should be considered when answering this question.
all the isomeric alcohols with the molecular formula cs5h;20 are added separately to warm
alkaline aqueous iodine.
how many of the isomers give a yellow precipitate?
a 0 b 1 cc 2 d 3

28 when compound x is heated with cr207“"/h", a colour change from orange to green is observed.
two tests are carried out on the organic product of this reaction.
tollens’ reagent no change
2,4-dinitrophenylhydrazine orange precipitate
what could be compound x?
a b cc d
o o oh oh

29 1 mole of each of the following four compounds is reacted separately with:

e anexcess of sodium

e anexcess of sodium carbonate.

which compound produces the same volume of gas with each of the two reagents?
a b cc d
oh o o [e)
oh
oh h ho
ho ho ho o

30 an infra-red spectrum shows a broad peak at 3000cm™ and a strong peak at 1710cm™’.
which substance could have produced this spectrum?
a methyl propanoate
b _propan-2-ol
c_propanoic acid
d_propanone

31. in an experiment, 10cm” of an organic compound, j, in the gaseous state is reacted with an
excess of oxygen. steam, 20cm? of carbon dioxide and 5cm? of nitrogen are the only products.
all gas volumes were measured at the same temperature and pressure.
what could be the identity of j?
1 cohen2
2 c2h3n
3. czh7n

32. in which pairs do both species have the same number of unpaired electrons in p orbitals?
1 oandcl*
2 f* and ga
3 nand kr*

33. in which reactions is the underlined element or compound reduced?
1 naclo + h,02 > o2 + nacl + h,0
2  2nh3 + 2li — 2linh2 + he
3  3ch3ch2oh + k2cr207 + 4h2so4, > 3ch3cho + cr2(sox)3 + k2so4 + 7h2o0

34 some polluting gases are removed from car exhaust fumes using a catalytic converter.

platinum or palladium can be used as the catalyst. the reactions are faster when platinum is the

catalyst than they are when palladium is the catalyst.

which statements are correct?

1 platinum acts as a heterogeneous catalyst in these reactions.

2 the palladium-catalysed reactions have higher activation energies than the
platinum-catalysed reactions.

3 the platinum-catalysed reactions are more exothermic than the palladium-catalysed
reactions.

35 which statements about ceramics are correct?
1 ceramics are good electrical conductors.
2 ceramics are strong materials.
3 ceramics have high melting points.

36 which types of bonding are present in ammonium carbonate, (nh4)2co3?
1 ionic
2 covalent
3 co-ordinate (dative covalent)

37 the diagram shows the structure of cholesterol.
cholesterol
ch,
ch,
ch,
ho
which statements about cholesterol are correct?
1. the molecule contains a secondary alcohol group.
2 the molecule contains two x bonds.
3 all carbon atoms in the four rings lie in the same plane.

38 chlorine atoms in the upper atmosphere cause the breakdown of ozone.
cl + o03 > op + clo
clo +o + cl + oq
which statements about these chlorine atoms are correct?
1. the chlorine atoms act as catalysts.
2 the chlorine atoms are free radicals.
3 the chlorine atoms are formed by heterolytic fission of a covalent bond in
chlorofluorocarbons.

39 the compounds listed are reacted with hydrogen cyanide.
which compounds produce a molecule containing a chiral centre?
1. butanal
2. butanone
3. pentan-2-one

40 carboxylic acids can be prepared from alcohols, nitriles or esters.
which statements are correct?
1 both primary and secondary alcohols can be oxidised to carboxylic acids.
2 carboxylic acids can be made from nitriles by hydrolysis.
3. ethyl propanoate gives propanoic acid when reacted with hydrochloric acid.

Solve 9701_m19_qp_12