chemistry

1. why is the first ionisation energy of phosphorus greater than the first ionisation energy of silicon?
a aphosphorus atom has one more proton in its nucleus.
b_ the atomic radius of a phosphorus atom is greater.
c_ the outer electron in a phosphorus atom is more shielded.
d_ the outer electron in a phosphorus atom is paired.

2 sodium peroxide, na2o2, is used to absorb carbon dioxide from the atmosphere and release
oxygen in closed environments such as space capsules and submarines.
2na202 + 2co2 > 2na2co3 + oo
which mass of sodium peroxide would be required to remove 2.4 dm*® of carbon dioxide from the
atmosphere at room temperature and pressure?
a 24g b 3.9g c 7.8g d 15.69

3 in which species are the numbers of protons, neutrons and electrons all different?
a za b #cr © %s* d %k*

4 calcium oxide and magnesium sulfide each react with acid.
cao(s) + 2h*(aq) > ca**(aq) + ho(i)
mgs(s) + 2h*(aq) > mg*(aq) + h2s(g)
a mixture of these two compounds, x, reacts with exactly 0.125 mol of dilute hydrochloric acid.
the amount of hydrogen sulfide formed is 0.0250 mol.
what was the mass of calcium oxide in mixture x?
a 14g b 21g c 28g d 42g

5 two moles of vo2’ ions react with one mole of zinc atoms in the presence of dilute acid. the
products include zn** ions and an ion, y. lon y contains vanadium. only zinc and vanadium
change oxidation state in the reaction.

what is ion y?
a vo; b vo* c vo" d vo,”*

6 the compound potassium bismuthate(v), kbios, is a powerful oxidising agent.
what is the significance of the (v) in potassium bismuthate(v)?
a _litis the oxidation number of the bismuth atom.
b itis the charge of the bismuthate ion.
c_itis the oxidation number of the bismuthate ion.
d_itis the sum of the charges of the two ions present.

7 hydrogen peroxide decomposes slowly at 20 °c to form water and oxygen.
2h202 == 2h20 + oo equilibrium constant = k,
the reaction is faster when a catalyst is present.
which statement is correct?
a_ the catalyst alters the boltzmann distribution so that the reactant molecules have more
energy.
b_ the catalyst has no effect on the value of k..
c_ the catalyst increases the value of k..
d_ the catalyst provides a different reaction mechanism with a higher activation energy.

8 adimer, q, is stable when solid but a dynamic equilibrium is set up in solution.
q(aq) = 2r(aq)
a solution of q has an initial concentration of 0.50 moldm~*. when equilibrium has been reached,
[q(aq)] has fallen to 0.25 moldm~.
the changes in [q(aq)] and [r(aq)] are plotted against time until equilibrium is reached. the
value of k, is then calculated.
which graph and value for k, are correct?
0.554,
0.4 ye
concentration 9.3 ee
a | jmoldn? 0.2 wor 1
014 °r
ot
0 time
0.55,
oa 2
. concentration 9-3 ie
/moldm3 0.2 wee 0.25
014 °r
o-t
0 time
0.554, ger sees
(e concentration 0.3 fhm 1
/moldm=* 024 /
6147"
ot
(e) time
0.5 aera seeeeeeeseee
ion 0.34 0 /
p | concentration fc cictsanii 2
/moldm 0.24 ;
aits*
ot
0 time

9 the reaction pathway for the forward reaction of a reversible reaction is shown.
30
energy pi scseons
/kj mol
50
progress of reaction

which statement is correct?
a the activation energy of the reverse reaction is +80 kj mol”.
b_ the enthalpy change for the forward reaction is +30 kj mol".
c the enthalpy change for the forward reaction is +50 kj mol”.
d_ the enthalpy change for the reverse reaction is +30 kj mol”.

10 ihe enthalpy changes tor the possible reactions w, x, y and z are given.

w naoh(aq) + hcl(aq) > nacl(aq) + h2o(l) ah°=-56kjmol™
x nacl(aq) + h,0(i) > naoh(aq) + hcl(aq) ah® = +56kjmol
y 2hi(g) > he(g) + 1x(g) ah® = +11kjmol™
z hg) + in(g) > 2hi(g) ah® =—11kjmol*

which statement about the activation energies of these reactions is correct?

a xis greater than w; z is greater than y.

b_ xis greater than w; y is greater than z.

c wis greater than x; z is greater than y.

d wis greater than x; y is greater than z.

11. the haber process is carried out with a nitrogen partial pressure of 50kpa, a hydrogen partial
pressure of 150 kpa, a temperature of 400°c and an iron catalyst.
n2(g) + 3h2(g) = 2nh3(g)
if all other conditions are kept the same, which change will result in a raised activation energy?
a both the nitrogen and hydrogen partial pressures are changed to 100 kpa.
b_ the iron is removed.
c_ the nitrogen partial pressure is increased to 150 kpa.
d_ the temperature is increased to 500°c.

12 the compound (ch3)3;3na/c13 has a simple molecular structure.
which statement about (ch3)3na/c1; is correct?
a (ch3)3naicl3 molecules attract each other by hydrogen bonds.
b_ the alatom in (ch3)3na/cl3 has an incomplete valence shell of electrons.
c_ the bonds around the alatom are planar.
d_ the molecules contain coordinate bonding.

13 vsepr theory should be used in answering this question.
the dot-and-cross diagram for an ozone, os, molecule is shown.
>
os oe
what is the predicted bond angle in this molecule?
a 107° b 109.5° cc 117° d = 120°

14 each of the substances shown is gaseous.
which substance is most likely to show ideal behaviour in the conditions shown?
[sae [ae
a carbon dioxide 250 1.00 x 10°
b hydrogen chloride 1000 1.00 x 10°
cc nitrogen 1000 1.00 x 10°
d oxygen 250 1.00 x 10°

15 which graph represents the variation of pressure p and volume v of a sample of an ideal gas at
constant temperature?
a b
| kn | zz
0 0
0 0
vv vv
cc d
| \ | he
0 0
0 0
vv v

16 use relevant enthalpy changes from the tables to answer this question.
c(s) + 2h2(g) > ch,(g) -76
ch4(g) + 202(g) > co.(g) + 2h20(g) 890
ch,(g) > c(g) + 4h(g) 1648
3c(s) + 4h(g) > c3he(g) -105
= a
/kj mol
h-h 436
cc-c 350
c=c 610
c=o 805
which value can be calculated for the enthalpy change for the following reaction?
2c(g) + 6h(g) > c2he(g)
a ~-2822kj mol’
b -2122kjmol™
c -1998kj mol"
d -1772kjmol™

17 element x requires strong heating to react with oxygen.
element x reacts with chlorine to give a covalently-bonded chloride.
what could be the identity of element x?
a magnesium
b_ phosphorus
c_ sodium
d silicon

18 the melting points of the period 3 elements sodium to aluminium are shown in the table.
feeomen [ne [ we [at |
which factor explains the increase in melting points from sodium to aluminium?
a the change in first ionisation energy from sodium to aluminium
b the increase in electronegativity from sodium to aluminium
c the increase in the a, of the elements from sodium to aluminium
d the increase in the number of outer electrons in each atom from sodium to aluminium

19 the nitrates of beryllium, calcium, magnesium and strontium all decompose in the same way
when heated. when 2.00g of one of these anhydrous nitrates is decomposed, 1.32g of gas is
produced.

what is the nitrate?

a _ beryllium nitrate
b_ calcium nitrate

c magnesium nitrate
d - strontium nitrate

20 inthe diagram, each test-tube w, x, y and z contains 25 cm? of a 0.1 moldm”™ solution of a salt.
ww x y z
25 4 25 4 25 +4 25 +4
bacl,(aq) mgc1,(aq) bacl,(aq) mgc1,(aq)
to test-tubes w and x, 25cm* of 0.1 moldm™ naoh(aq) is added.
to test-tubes y and z, 25cm? of 0.1 moldm™ h,so,(aq) is added.
in which of test-tubes w and x does the liquid have the higher ph and which of test-tubes y and
z has the greater mass of precipitate?
. greater mass
| higher ph of precipitate
a ww ¥
b ww z
cc x ¥
d x z

21 what is the oxidation state of the chlorine-containing species that kills bacteria in drinking water?
a -1 b +1 cc +3 d +5

22 compound q is a white crystalline solid which dissolves easily in water.
when concentrated sulfuric acid is added to a dry sample of q, steamy white fumes are formed.
when these white fumes are passed into aqueous silver nitrate solution, a white precipitate
forms.
this precipitate is soluble in dilute ammonia solution.
what is compound q?
a agcl b nabr c nacl d  pbbr2

23 risa solid. r fizzes when hydrochloric acid is added.
r reacts with hot aqueous sodium hydroxide, giving off a gas which turns red litmus blue.
what is the formula of r?
a nh,co3 b  (nha)2co3 c (nh4)2hco3; =d  (nha4)2so4

24 photochemical smog is a type of air pollution produced in urban areas by the effect of sunlight on
substances released from vehicle exhausts.
which mixture of primary pollutants leads to the formation of photochemical smog?
a carbon dioxide and water vapour
b_ carbon monoxide and unburnt hydrocarbons
c__ nitrogen oxide and unburnt hydrocarbons
d _ sulfur dioxide and water vapour

25 t is an element in period 3.
the first ionisation energy of t is lower than that of the element with one less proton.
the oxide of t does not react with water.
what is the identity of t?
a aluminium
b -s silicon
c_ sodium
d - sulfur

26 the structure of tartaric acid is shown.
tartaric acid
oh o
ho.
oh
(6) oh
which statements about tartaric acid are correct?
1 amolecule of tartaric acid has more than one chiral centre.
2 the molecular formula of tartaric acid is c4h4og.
3 one molecule of tartaric acid produces four hydrogen ions in aqueous solution.
a 1,2and3 b 1and2only c 2and3only' d = 1only

27 a carboxylic acid, p, has no 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

28 which pair includes a hydrocarbon without a chiral centre?
a  ch3ch2ch2ch(ch3)ch2ch3 =ch3ch(ch3)ch(ch3)ch2chs3
b  chsch2ch2ch(ch2ch3)ch3 =ch3ch2ch2ch(ch3)ch2ch3
c chsch2ch2ch(ch3)ch2ch3 9=ch3ch2ch(ch3)ch(chs)2
d chsch(ch2ch3)ch(ch3)ch3 =ch3ch(ch3)ch2ch(chs)2

29 what is the major product formed when compound r is warmed with an excess of hbr?
r
oh
oh
a b cc d
ee ee e—=—h

30 cis-but-2-ene reacts with cold dilute acidified potassium manganate(vii) solution to give
product x.
cis-but-2-ene reacts with hot concentrated acidified potassium manganate(vii) solution to give
product y.
which row describing the reactions of x and y is correct?
when sodium metal is added to when sodium hydroxide solution is
separate samples of x and y added to separate samples of x and y

a both x and y will react neither x nor y will react

b both x and y will react only one of x and y will react

cc only one of x and y will react neither x nor y will react

d only one of x and y will react only one of x and y will react

31. for which reaction will the major organic product have the lowest relative molecular mass?
a_ bromoethane is heated under reflux with an aqueous solution of sodium hydroxide.
b_ bromoethane is heated under reflux with a solution of sodium cyanide in ethanol.
c  2-bromopropane is heated under reflux with an aqueous solution of sodium hydroxide.
d  2-bromopropane is heated under reflux with concentrated ethanolic sodium hydroxide.

32 c,h cl reacts with warm dilute aqueous sodium hydroxide solution.
which isomer of c4hgcl will form the most stable cation intermediate?
a_ 1-chlorobutane
b 2-chlorobutane
c_1-chloro-2-methylpropane
d  2-chloro-2-methylpropane

33 1.0mol of an organic compound, j, requires 6.0 mol of oxygen for complete combustion.
1.0 mol of j reacts with sodium, producing 0.50 mol of a gas that gives a ‘pop’ with a lighted splint.
j reacts with an excess of hot acidified potassium manganate(vii) to produce an organic
compound which gives an orange-red precipitate with 2,4-dnph reagent.
which compound is j?
a but-1-ene
b butan-2-ol
c_propan-2-ol
d  2-methylpropan-2-ol

34 structural isomerism and stereoisomerism should be considered when answering this question.
3-methylhexan-3-ol reacts with hot concentrated sulfuric acid to form several isomeric
compounds with the molecular formula c7h14.

3-methylhexan-3-ol
oe
how many isomeric compounds could be formed in this reaction?
a 3 b 4 cc 5 d 6

35 the table shows a student's predictions for the reactions of three compounds.
alkaline fehling’s tollens’
compound
i,(aq) reagent reagent
key
q se v ri v /¥ = reaction occurs
x = no reaction
[e)
2 db v x x
[e)
3 — x x x
which rows show the correct predictions?
a 1,2and3 b 1tand2only c 1and3only d 2and3only

36 which mechanism describes the reaction of aldehydes and ketones with hcn + nacn?
a electrophilic addition
b _ electrophilic substitution
c nucleophilic addition
d nucleophilic substitution

37 propyl propanoate can be synthesised in three steps using propanenitrile as the only organic
starting material.
in step 1, the nitrile is converted into compound x.
in step 2, compound x is converted into compound y.
in step 3, compound y is reacted with more of compound x to give propyl propanoate.
step 1 step 2 step 3
ch3ch2cn ————> x ————> y ———> ch3ch2co2ch2ch2ch3

which reagents are suitable for carrying out step 1 and step 2?
p| set [sep |

a hcl(aq) conc. h2so,

b hcl(aq) lialh,

cc naoh(aq) conc. h2so4

d naoh(aq) nabh,

38 the ester ch3ch2co2ch3 is hydrolysed by boiling with aqueous sodium hydroxide.
which compound is one of the products?
a ethanol
b_propan-1-ol
c_ sodium methanoate
d sodium propanoate

39 compound v polymerises to form polymer w. a section of polymer w is shown.
polymer w
polymerisation or on st pcr pt
e* @* &
what is the correct name of compound v?
a$ 1,1,2-trichlorobutene
b 1,1,2-trichloroethene
c §1,1,2-trichloropropene
d 1,1,2-trichloro-2-methylethene

40 a molecule of an organic compound, p, contains three carbon atoms and shows a strong
absorption at 1720cm’’ in its infrared spectrum.
p is reacted with an excess of hot acidified potassium dichromate(vi) forming organic product q.
q shows a strong absorption at 1700 cm™ and a strong, broad absorption centred at 2800 cm“ in
its infrared spectrum.
bond | functional group containing the bond | characteristic infrared absorption range
(in wavenumbers)/cm
hydroxy, ester 4040-1300
aromatic compound, alkene 1500-1680
c=o | amide 1640-1690
carbonyl, carboxyl 1670-1740
ester 1710-1750
o-h_| carboxyl 2500-3000
hydroxy 3200-3600
what is p?
a _propanal
b_propanone
c_propan-t-ol
d_propan-2-ol

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