OCR B Salters A Level Chemistry –
Comprehensive Revision Questions and
Answers, UK A Level Chemistry –
Complete exam-focused revision material
Introduction:
This document contains a comprehensive collection of OCR B
Salters A Level Chemistry revision questions with clear,
concise answers covering physical, organic, and inorganic
chemistry. Topics include energetics, kinetics, equilibrium,
redox, electrolysis, atomic structure, bonding, organic
mechanisms, fuels, the atmosphere, analytical tests, and
practical techniques. The material is well suited for OCR B
Salters students preparing for mocks, final A Level exams, or
structured topic-by-topic revision.
Exam Questions and Answers:
Ways to measure the rate of a reaction ---Correct Answer----
Volume of gas formed
-Mass lost
-pH
-Colorimetry
,-Chemical analysis (samples removed at regular intervals,
quenched and analysed using technique such as titration)
Maxwell-Boltzmann distribution ---Correct Answer---Shows
the spread of energies that molecules of gas or liquid have at a
particular temperature
How do homogeneous catalysts work? ---Correct Answer---The
catalyst reacts with the reactants to form an intermediate. The
intermediate then breaks down to give the product and
regenerates the catalyst
How do chlorine atoms catalyse decomposition of ozone? ---
Correct Answer----Chloromethane in the stratosphere is spilt
apart by radiation
-Chlorine radicals react with ozone :
Cl. + O3 --> ClO. + O2
.Both chlorine and oxygen radicals compete to breakdown
ozone
.ClO. radical reacts with oxygenatom to form :
ClO. + O --> Cl + O2
,How do hydroxyl radicals deplete the ozone layer? ---Correct
Answer----HO radicals formed by the reaction of H2O and O
atoms in stratosphere
-Acts as homogenous catalyst
-HO. Reacts with O3 :
HO. + O3 --> O2 + HO2.
-HO2. radicals react with O atoms to reform HO. radicals
HO2. + O --> HO. + O2
Physical appearance of halogens at room temperature? ---
Correct Answer---F - pale yellow gas
Cl - pale green gas
Br - dark red liquid
I - shiny black solid / purple vapour
Appearance of halogens dissolved in water / cyclohexane? ---
Correct Answer---Cl - pale green
Br - orange yellow / ornage brown
I - brown / violet
, Why dissolve halogens in cyclohexane? ---Correct Answer---
Halogens are more soluble in non-polar solvents, colours more
distinctive
Which halogen is the strongest oxidising agent? ---Correct
Answer---Fluorine
How to distinguish between halide ions in silver nitrate test? --
-Correct Answer---Ad to ammonia solution:
Silver chloride (white) is most soluble (goes colourless)
Silver bromide (cream) is less soluble (cloudy)
Silver iodide is insoluble (yellow) (opaque)
List the chlorate ions ---Correct Answer---ClO- (chlorate 1)
ClO2 - (chlorate 3)
ClO3 - (chlorate 5)
ClO4 - (chlorate 7)
How to write expression for equilibrium constant ---Correct
Answer---Products on top, reactants on bottom, raised to the
power of the number of moles in balanced equation
Comprehensive Revision Questions and
Answers, UK A Level Chemistry –
Complete exam-focused revision material
Introduction:
This document contains a comprehensive collection of OCR B
Salters A Level Chemistry revision questions with clear,
concise answers covering physical, organic, and inorganic
chemistry. Topics include energetics, kinetics, equilibrium,
redox, electrolysis, atomic structure, bonding, organic
mechanisms, fuels, the atmosphere, analytical tests, and
practical techniques. The material is well suited for OCR B
Salters students preparing for mocks, final A Level exams, or
structured topic-by-topic revision.
Exam Questions and Answers:
Ways to measure the rate of a reaction ---Correct Answer----
Volume of gas formed
-Mass lost
-pH
-Colorimetry
,-Chemical analysis (samples removed at regular intervals,
quenched and analysed using technique such as titration)
Maxwell-Boltzmann distribution ---Correct Answer---Shows
the spread of energies that molecules of gas or liquid have at a
particular temperature
How do homogeneous catalysts work? ---Correct Answer---The
catalyst reacts with the reactants to form an intermediate. The
intermediate then breaks down to give the product and
regenerates the catalyst
How do chlorine atoms catalyse decomposition of ozone? ---
Correct Answer----Chloromethane in the stratosphere is spilt
apart by radiation
-Chlorine radicals react with ozone :
Cl. + O3 --> ClO. + O2
.Both chlorine and oxygen radicals compete to breakdown
ozone
.ClO. radical reacts with oxygenatom to form :
ClO. + O --> Cl + O2
,How do hydroxyl radicals deplete the ozone layer? ---Correct
Answer----HO radicals formed by the reaction of H2O and O
atoms in stratosphere
-Acts as homogenous catalyst
-HO. Reacts with O3 :
HO. + O3 --> O2 + HO2.
-HO2. radicals react with O atoms to reform HO. radicals
HO2. + O --> HO. + O2
Physical appearance of halogens at room temperature? ---
Correct Answer---F - pale yellow gas
Cl - pale green gas
Br - dark red liquid
I - shiny black solid / purple vapour
Appearance of halogens dissolved in water / cyclohexane? ---
Correct Answer---Cl - pale green
Br - orange yellow / ornage brown
I - brown / violet
, Why dissolve halogens in cyclohexane? ---Correct Answer---
Halogens are more soluble in non-polar solvents, colours more
distinctive
Which halogen is the strongest oxidising agent? ---Correct
Answer---Fluorine
How to distinguish between halide ions in silver nitrate test? --
-Correct Answer---Ad to ammonia solution:
Silver chloride (white) is most soluble (goes colourless)
Silver bromide (cream) is less soluble (cloudy)
Silver iodide is insoluble (yellow) (opaque)
List the chlorate ions ---Correct Answer---ClO- (chlorate 1)
ClO2 - (chlorate 3)
ClO3 - (chlorate 5)
ClO4 - (chlorate 7)
How to write expression for equilibrium constant ---Correct
Answer---Products on top, reactants on bottom, raised to the
power of the number of moles in balanced equation
