chemistry

1. in which species are the numbers of protons, neutrons and electrons all different?
a &f b 7na* c ip d %s?-
nee ne ee ee

2 which would contain 9.03 x 10 oxygen atoms?
a 0.25mol aluminium oxide
b 0.75mol sulfur dioxide
c  1.5mol sulfur trioxide
d  3.0mol water

3. in some fireworks there is a reaction between powdered aluminium and powdered barium nitrate.
heat is evolved, an unreactive gas is produced, and all nitrogen atoms are reduced.
what is the equation for this reaction?
a 2al + ba(no3)2 + al2o3 + bao + 2no
b 4al + 4ba(no3)2 > 2ai,03 + 4ba(no2). + o2
c 10al + 3ba(nos3)2 — 5al2,03 + 3bao + 3n2
d 10al + 18ba(no3)2 > 10ai(no3)3 + 18bao + 3n2

4 which organic compound has the highest boiling point?
a c(chs)4
b  ch3ch2,ch2ch2ch3
c ch3coch2ch3
d chsch(oh)ch2ch3

5 ata temperature of 2500k and a pressure of 1.00 x 10 pa a sample of 0.321 g of sulfur vapour
has a volume of 2.08 x 10°m*.
what is the molecular formula of sulfur under these conditions?
a ss b s cc ss d ss

6 which reaction involves a decrease in the bond angle at a carbon atom?
a_ bromoethane refluxed with ethanolic sodium hydroxide
b complete combustion of methane in air
c_ ethanol heated with conc. h2so4
d_ polymerisation of ethene

7 inthe high temperatures of car engines, nitrogen reacts with oxygen to give nitrogen monoxide.
4n2(g) + $0o2(9) > no(g) ah® = +90kj mol
this reaction has activation energy e..
which reaction pathway diagram could correctly represent this reaction?
a b
_|fs \.no@)
un “ ing iy = ing, als

8 areaction sequence is shown.
1 2 3 4
so, ——» so; ———» h,so, ———® h,s ——» so,

in each stage of this sequence the sulfur is oxidised, reduced or neither oxidised nor reduced.
which row is correct?
ee ee ee

a neither oxidised reduced reduced

b oxidised neither reduced reduced

cc oxidised neither reduced oxidised

d oxidised oxidised reduced oxidised

9 hydrogen and carbon dioxide gases are mixed at 800k. a reversible reaction takes place.
h(g) + co(g) = h,0(g) + co(g)
at equilibrium, the partial pressures of hz and co, are both 10.0 kpa. k, is 0.288 at 800k.
what is the partial pressure of co in the equilibrium mixture?
a 5.37kpa b 18.6kpa c 28.8kpa d 347kpa

10 a reaction involved in the contact process is shown.
2s0.(g) + o2(g) = 2s03(g) ah® = -197kj mol"
the reaction is investigated at 200 kpa and 700k and the value of the equilibrium constant, kp, is
found to be y. the reaction is then investigated at 1000kpa and 700k and the value of k, is
found to be z.
which statement comparing y and z is correct?
a y and zare the same.
by is greater than z.
c zis 2.2 times greater than y.
d zis 5.0 times greater than y.

11 the boltzmann distribution for the hydrogenation of an alkene at a particular temperature in the
absence of a catalyst is shown.
proportion
of molecules e,
with energy e '
0%
molecular energy e
which row correctly describes the effects of adding nickel to the reaction vessel?
ancl eel activation energy, e.
boltzmann distribution gy ke
a changes decreases
b changes increases
cc does not change decreases
d does not change increases

12 the elements magnesium and sulfur each form doubly charged ions.
how do the atomic radii and ionic radii of these elements compare?

atomic ionic | atomic ionic
radius radius | radius radius

a mg > mg* s > gf

b mg >  mg** ss <

cc mg <  mg* is >

d mg < mg is <

13 which graph correctly shows relative electronegativity plotted against relative atomic radius for
the elements na, mg, al and si?
a b
si
0)
al al
. ® ®
electronegativity mg electronegativity mg
[)
si na na
© [o} (0)
atomic radius atomic radius
cc d
na si
(0) 0}
mg al
© (0)
electronegativity al electronegativity mg
[)
[)
si na
() (9)
atomic radius atomic radius

14 trends are seen in the physical and chemical properties of the elements of group 2 and their
compounds.
which property shows a decrease from magnesium to barium?
a the rate of the reaction between the element and dilute hydrochloric acid
b _ the solubility of the hydroxides
c the solubility of the sulfates
d_ the temperature of decomposition of the carbonates

15 calcium oxide is added to water and the resulting mixture is filtered.
this filtrate is x.
when carbon dioxide is bubbled through filtrate x, a white precipitate is formed.
which equation for this reaction of filtrate x with carbon dioxide is correct?
a cao + coz > caco;
b ca(oh). + co2 + cao + h,co;
c 2cao + h20 + coz2 > caco; + ca(oh)2
d ca(oh). + coz + caco; + h20

16 element x reacts with cold, dilute, aqueous sodium hydroxide to form two different
chlorine-containing products, y and z.
what are the oxidation states of chlorine in y and z?
p| vy [2 |
a 0 +1
b 0 +5
cc -1 +1
d -1 +5

17 a powder is known to be either a single sodium halide or a mixture of two sodium halides. a
sample of the powder was dissolved in water.
aqueous silver nitrate was added, and a pale yellow precipitate was formed. when concentrated
aqueous ammonia was then added, this precipitate partly dissolved leaving a darker yellow
precipitate.
what might the powder be?
a sodium bromide only
b sodium iodide only
c  amixture of sodium chloride and sodium bromide
d  amixture of sodium chloride and sodium iodide

18 the ammonium ion is formed by the following reaction.
nh3 + h* —> nh,"
which statement about the species involved in this reaction is correct?
a the ammonia molecule contains a dative covalent bond.
b the ammonium ion is a bronsted-lowry base as it has accepted a proton.
c the h-n-h bond angle changes from 107° in ammonia to 90° in the ammonium ion.
d the number of electrons surrounding each nitrogen atom does not change.
ott escsc—“#een

19 a chemist took 2.00dm°” of nitrogen gas, measured under room conditions, and reacted it with a
large volume of hydrogen gas to produce ammonia. only 15.0% of the nitrogen gas reacted to
produce ammonia.

which mass of ammonia was formed?
a 0.213g b 0.425g c 1.42g d 2.83g

20 a carbonyl compound x will react with hcn in the presence of nacn to make a compound with
m, 85. compound x does not react with fehling’s reagent.
what is x?
a _butanal
b_butanone
c _propanal
d_propanone

21 geraniol and linalool are compounds found in some flower fragrances.
ch, ch,
u ch,oh ho...
07 som h,c~ ~c—h
how * ier the,
ch ch
ae “ch, be” “ee,
geraniol linalool
which statement is correct?
a they are chain isomers of each other.
b_ they are geometrical isomers of each other.
c_ they are optical isomers of each other.
d_ they are positional isomers of each other.

22 vwvnicn equation represents the initiation step of the substitution reaction between metnane and
chlorine?
a chyg > chg* + he
b ch, > ch; + h*
c clp > 2cle
d ch > cl’ + cr

23 aqueous sodium hydroxide reacts with 1-bromopropane to give propan-1-ol.
what should be included in a diagram of the first step in the mechanism?
a acurly arrow from a lone pair on the oh” ion to the c* atom of 1-bromopropane
bacurly arrow from the c* atom of 1-bromopropane to the oh” ion
c_ acurly arrow from the c—br bond to the c atom
d_ the homolytic fission of the c-br bond

24 a sample of 2.76g of ethanol was mixed with an excess of aqueous acidified potassium
dichromate(vi). the reaction mixture was then boiled under reflux for one hour. the required
organic product was then collected by distillation.

the yield of product was 75.0%.
which mass of product was collected?
a 1.26g b 1.989 c 2.07g d 2.70g

25 compound x is a single, pure, optical isomer. x is heated with an excess of concentrated h2sox..
only one organic product is formed.
what could x be?
a b cc d
oh
mod oc ; ; oe

26 2-bromo-2-methylpropane undergoes nucleophilic substitution when heated under reflux with an
aqueous solution of sodium hydroxide.
which row is correct?
mechanism for
fi f reason
this reaction
a sy1 the hydroxide ion is helped in its approach to
the central carbon atom by the methyl groups
b sn1 the intermediate carbocation is stabilised
by the inductive effect of the methyl groups
cc sn2 the hydroxide ion is hindered in its approach to
the central carbon atom by the methyl groups
d sn2 the intermediate carbocation is destabilised
by the inductive effect of the methyl groups

27 h2nnhcgh3(noz)2 is the structural formula of 2,4-dnph.
many, but not all, organic reactions need to be heated before reaction occurs.
which reaction occurs at a good rate at room temperature (20°c)?
a ciph22 > cahig + cohg
b  ch3ch2ch2br + nh3 — ch3ch2ch2nh2 + hbr
c ch3ch20h + kbr > ch3ch,br + koh
d (chs)2,co + h2nnhcgsh3(no2)2 — (ch3)2c=nnhcsh3(no2)2 + h2o

28 a carboxylic acid, p, has no possible chain isomers. it reacts with an alcohol, q, that has only
one positional isomer.
what could be the ester formed from a reaction between p and q?
a butyl propanoate
bethyl butanoate
c pentyl ethanoate
d propyl pentanoate

29 which compound is chiral and reacts with na,co3 to give co2?
a b cc d
i co,h ch, (oh jee ch(br)co,h
“ow hco,ch |
| 5 1"
cc ch,
h~ “co,h ch,

30 which compound, when hydrolysed, gives propanoic acid and propan-2-ol?
a  ch3ch2co2ch2ch(ch3)chs
b  (chs)2,chco2ch2ch3
c ch3ch2co2ch(ch3)chs
d ch3;ch2ch,co,ch(ch3)chs

31 an isolated gaseous atom of element x has paired electrons in at least one of its 3d orbitals and
has a filled 4s subshell.
what could be the identity of element x?
1 iron
2 gallium
3 copper

32 which allotropes of carbon have a giant molecular structure?
1. buckminsterfullerene
2 diamond
3. graphite

33 which statements about endothermic reactions are correct?
1 on the reaction pathway diagram the products of the reaction are lower than the reactants.
2 ‘there is a net transfer of heat energy from the surroundings to the reacting system.
3. the total bond energies of the reactants > the total bond energies of the products

34 the rate of chemical reactions can be increased by the addition of a suitable catalyst.
for which reactions can a heterogeneous catalyst be used?
1 no + 3h. = 2nh3
2 2802 + o2 = 2803
3. 2no + 2co = no + 2co2

35 which chlorides, when added to water, can produce a solution with a ph of less than 5?
1 sicl,
2 aici
3 mgcl,

36 acid rain continues to be a problem.
which statements about acid rain are correct?
1 acid rain is formed when oxides of nitrogen or oxides of sulfur react with water in the
atmosphere.
2 acid rain causes an increase in the concentration of heavy metal ions in water courses.
3. nitrogen dioxide will catalyse the formation of so3 from soz in the atmosphere.

37 which compounds contain a chiral centre?
1. 2-hydroxybutanoic acid
2  3-hydroxybutanoic acid
3. 4-hydroxybutanoic acid

38 the diagram shows the monomer used to make polyvinyl chloride, pvc.
h h
. ae
c=c
/ n\
h cl
assuming that one particular molecule of the polymer forms from n molecules of the monomer
(where n is many thousands), which statements are correct?
1. the relative molecular mass of this polymer molecule is approximately 62.5n.
2. there are n chiral carbon atoms in this polymer molecule.
3 there are 5n o bonds in one polymer molecule.

39 an organic compound, x, has the following skeletal formula.
poe
x
which statements about x are correct?
1. xisa primary alcohol.
2  xwill dehydrate to give a single alkene.
3  xwill undergo a substitution reaction with chloride ions.

40 2,2,4-trimethylpentanal is used in the manufacture of adhesives.
which reagents would 2,2,4-trimethylpentanal react with?
1. 2,4-dinitrophenylhydrazine reagent
2 tollens' reagent
3. alkaline aqueous iodine

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