Which of these processes are endothermic?
I. Condensing
II. Subliming
III. Melting
I and II only
I and III only
II and III only
I, II and III
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Syllabus Edition
First teaching 2014
Last exams 2024
Which of these processes are endothermic?
I. Condensing
II. Subliming
III. Melting
I and II only
I and III only
II and III only
I, II and III
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Ethanoic acid has the formula CH3COOH. How many carbon atoms are present in 0.1 mol of ethanoic acid?
6.0 x 1022
1.2 x 1023
6.0 x 1023
1.2 x 1024
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A periodic table is needed for this question
Excess aqueous cold sodium hydroxide is reacted with 0.10 mol of chlorine gas, Cl2. One of the products is a compound of sodium, oxygen and chlorine.
What mass of the product is formed?
3.54 g
7.44 g
14.8 g
26.6 g
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A periodic table is needed for this question
Chicken eggs are made up of 5% by mass of egg shell. The average egg has a mass of 50 g.
Assume that chicken eggshell is pure calcium carbonate.
How many complete chicken’s egg shells would need to neutralise 50 cm3 of 2.0 mol dm-3 ethanoic acid?
4
3
2
1
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The phosphide ion, , is used in medicine as a radiotherapy treatment for some forms of cancer.
What is the composition of the phosphide ion?
protons |
neutrons |
electrons |
|
A B C D |
15 15 17 17 |
17 17 15 15 |
32 18 15 32 |
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Which statements correctly describe the distribution of mass and charge in the atom?
1 |
the negative charge is concentrated in one area outside the nucleus |
2 |
the mass is concentrated inside the nucleus |
3 |
the negative charge is spread around outside the nucleus |
1 and 3
1 and 2
2 and 3
1, 2 and 3
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Which of the following statements describes first ionisation energy?
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The electronegativity of four elements are given below
N = 3.0 H = 2.1 F = 4.0 P = 2.1
What is the correct order of polarity for the following compounds
PH3 < PF3 < NF3 < NH3
PH3 < PF3 < NH3 < NF3
NF3 < NH3 < PH3 < PF3
PH3 < NH3 < NF3 < PF3
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Which of the species shown below does not have resonance structures?
C6H6
CO32-
C2H4
O3
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What is the strongest type of intermolecular force exhibited in the amino acid molecule serine?
London dispersion forces
Permanent dipole permanent dipole forces
Hydrogen bonding
Covalent bonding
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Which of the following molecules will have the highest boiling point?
CH3CH2CHO
CH3CH2CH2NH2
CH3CH2OCH3
CH3CH2CH2F
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An experiment was carried out to determine the approximate value for the molar enthalpy change of neutralisation.
75 cm3 of 3.00 mol dm–3 hydrochloric acid was placed in a polystyrene beaker of negligible heat capacity. Its temperature was recorded, and then 75 cm3 of
3.00 mol dm−3 potassium hydroxide at the same temperature was quickly added, and the solution stirred.
The temperature rose by 14 °C. The resulting solution may be considered to have a specific heat capacity of 4.18 J g-1 K-1.
Which calculation below is correct?
J mol-1
J mol-1
J mol-1
J mol-1
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The equations below show the formation of sulfur oxides from sulfur and oxygen.
S(s) + O2(g) → SO2(g) = –297 kJ mol–1
S(s) + 1½O2(g) →SO3(g) = –395 kJ mol–1
What is the enthalpy change of reaction,,of 2SO2(g) + O2(g) → 2SO3(g) in kJ mol–1?
(794 − 594)
(296 + 395)
(− 395 + 297)
(−790 + 594)
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The reaction pathway for a reversible reaction is shown below:
Which statement is correct?
The activation energy of the reverse reaction is +90 kJ mol–1
The activation energy of the forward reaction is +20 kJ mol–1
The activation of the reverse reaction is +20 kJ mol–1
The enthalpy change of forwards reaction is - 70 kJ mol–1
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The diagram shows the skeletal formula of cyclobutane.
The enthalpy change of formation of cyclobutane is +75.1 kJ mol–1, and the enthalpy change of atomisation of graphite is +712 kJ mol–1.
The bond enthalpy of C–H is 414 kJ mol–1 and of H–H is 436 kJ mol–1.
What is the average bond enthalpy of the C–C bond in cyclobutane?
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The energies of the reactants, the products and the transition state of a reaction are shown in the reaction pathway diagram below.
Which expression correctly represents how to calculate the activation energy of the forward reaction?
E1 – E2
E2 – E1
E2 – E3
E3 – E2
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Bleach solution contains sodium chlorate (I) which naturally decomposes according to the equation below:
2NaClO (aq) → 2NaCl (aq) + O2 (g)
The bleach decomposes faster as the temperature increases. A 100 cm3 sample of 10% bleach was heated to 40 C and the amount of oxygen evolved was measured against time.
The experiment was repeated under the same conditions, but this time using a 100 cm3 sample of 20% bleach. If the first experiment produces the dotted line, which line is produced by the second experiment?
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The dissociation of gas X2Y4 into XY2 is represented in the equation below:
X2Y4 (g) ⇌ 2XY2 (g) = +60 kJ mol-1
At constant pressure, if the temperature of the equilibrium mixture of the gases is increased, will the volume of the mixture increase or decrease and why?
the volume will increase, but only because of a shift of equilibrium towards the right
the volume will increase, both because of a shift of equilibrium towards the right and also because of thermal expansion
the volume will stay the same because any thermal expansion could be exactly counteracted by a shift of equilibrium towards the left
the volume will decrease because a shift of equilibrium towards the left would more than counteract any thermal expansion
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The following Kc values were obtained for a reaction carried out at different temperatures, T1 to T4.
Temperature |
Kc value |
T1 |
1 x 10-2 |
T2 |
1 x 101 |
T3 |
1 |
T4 |
1 x 102 |
Which of the following gives the correct amount of products in the mixtures from least to most?
T1 <T2 <T3<T4
T4 <T3 <T2<T1
T4 <T2 <T3<T1
T1 <T3 <T2<T4
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What role does each species play in the equilibrium below according to Brønsted-Lowry theory?
CH3COOH + HCl ⇌ CH3COOH2+ + Cl-
|
CH3COOH |
HCl |
CH3COOH2+ |
Cl- |
A |
acid |
base |
base |
acid |
B |
acid |
base |
acid |
base |
C |
base |
acid |
base |
acid |
D |
base |
acid |
acid |
base |
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Four 1.0 M solutions of HCl, NH3, NaOH and CH3COOH have been mislabelled, but a student has a pH meter to test the pH of the solutions. Arrange the solutions in order of increasing pH:
HCl (aq) < NH3 (aq) < NaOH (aq) < CH3COOH (aq)
CH3COOH (aq) < HCl (aq) < NH3 (aq) < NaOH (aq)
HCl (aq) < CH3COOH (aq) < NH3 (aq) < NaOH (aq)
NaOH (aq) < NH3 (aq) < CH3COOH (aq) < HCl (aq)
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The pH of clean rain water is around 5.5. Which substance is responsible for this?
Methane
Carbon dioxide
Nitrogen oxides
Sulfur dioxide
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Which row correctly describes oxidation and reduction in terms of the transfer of electrons and changes in oxidation state?
|
Transfer of electrons |
Change in oxidation state |
||
|
oxidation |
reduction |
oxidation |
reduction |
A B C D |
gain loss loss gain |
loss gain gain loss |
increase increase decrease decrease |
decrease decrease increase increase |
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What is formed at the electrodes during the electrolysis of molten potassium iodide?
|
Positive electrode |
Negative electrode |
A |
K+ |
I- |
B |
K |
I2 |
C |
I- |
K+ |
D |
I2 |
K |
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Which features about the members of a homologous series are correct?
I and II only
I and III only
II and III only
I, II and III
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What is the correct IUPAC name for the molecule shown?
ethoxyethane
methoxyethane
propanone
propanal
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In the hydrolysis of bromoethane by aqueous sodium hydroxide, what is the nature of the attacking group and of the leaving group?
|
attacking group |
leaving group |
A B C D |
electrophile electrophile nucleophile nucleophile |
electrophile nucleophile electrophile nucleophile |
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A periodic table is needed for this question
Which compound has an Mr of 84.18 and will react with HBr to give a product with an Mr of 165.09?
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Bromine exists as two isotopes 79Br and 81Br, which are found in almost equal abundance.
Which of the following statements is correct?
79Br is more reactive than 81Br
The mass spectrum of C3H7Br has two molecular ion peaks at 122 and 124
The atomic radius of 79Br is less than the atomic radius of 81Br
The first ionisation energy of 79Br is less than the first ionisation energy of 81Br
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Which alcohol is likely to have a fragment ion at m/e = 31 in its mass spectrum?
(CH3)2CHCH2OH
CH3CH(OH)CH2CH2CH3
CH3CH2CH2C(OH)(CH3)2
CH3CH2CH(OH)CH3
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