A LEVEL CHEMISTRY B (SALTERS):
FUNDAMENTALS OF CHEMISTRY
COMPREHENSIVE STUDY GUIDE 2026 FULL
QUESTIONS AND SOLUTIONS GRADED A+
◍ How does a substitution reaction make haloaklanes?.
Answer: -Presence of strong acid-H+ adds to a lone pair on O atom of
alcohol-C atom bonded to O now has higher partial positive charge-C atom
attacked by halide ion (nucleophile)-Products are haloalakne and water
◍ Reactivity trend of haloalkanes?.
Answer: More reactive down group 7 as weaker bond enthalpy due to outer
electrons being further from nucleus, not affected by bond polarity
◍ What is core charge?.
Answer: The core charge of an atom is a measure of the attractive force felt
by the valence shell electrons towards the nucleus. Calculated as total proton
charge - total inner electron charge
◍ What is activation energy?.
Answer: The energy with which a pair of molecules must collide in order to
react
◍ Equation for atom economy?.
Answer: Atom economy = Relative formula mass of desired products /
Relative formula mass of all reactants x 100
◍ What is a co-product?.
Answer: A valuable substance that is produced as well as the intended
product as a result of the reaction that produce the intended product
◍ How is HCl often made as a co-product?.
, Answer: Co-product of chlorination of organic compounds
◍ Which halide is the best reducing agent?.
Answer: Iodide
◍ How to make hydrogen fluoride/chloride?.
Answer: .React NaF/Cl with conc H2SO4 to make HF/Cl gas.You will see
white fumes of HCl .Not redox
◍ Why can't you make make hydrogen bromide/iodide by reacting sulfuric
acid with sodium bromide/iodide?.
Answer: .Br/I are too strong of reducing agents.Br/I reduce sulfuric aid to
sulfur dioxide.Product will a mix of hydrogen Br/I gas, sulfur dioxide and
Br/I vapour
◍ Ionic equation how bromide from HBr reduces sulfuric acid?.
Answer: 2H+ + 2Br- + H2SO4 --> SO2 + Br2 + 2H20
◍ What happens when sodium bromide reacts with concentrated sulfuric
acid?.
Answer: -Initially HBr and NaHSO4 formed-Then Br- reduces sulfuric acid
to sulfur dioxide, and produces bromine and water
◍ How can you produce hydrogen iodide/bromine?.
Answer: React sodium iodide/bromide with concentrated phosphoric acid, as
it is not so easily reduced as sulfuric acid
◍ Explain the thermal stability trend of the hydrogen halides.
Answer: Hydrogen halides get less thermally stable down the group because
bond H-Halide bond strength decreases
◍ Acidity of hydrogen halides.
Answer: HCl, HBr, and HI form stronger acids than HF, in solution, because
they dissociate into their ionse.g HCl(aq) -> H+(aq) + Cl-(aq)or H20(l) +
HCl(aq) -> H3O+(aq) + Cl-(aq)
◍ What reaction takes place between ammonia and hydrogen halides and how
to tell if it has occured?.
, Answer: .H-halides react with ammonia to make salts egNH3 (g) + HCl (g)
--> NH4Cl (g).Glass rod dipped in conc ammonia solution placed in
H-halide, white cloud of ammonium halide made
◍ How do solid hydrogen halides react with sulfuric acid?.
Answer: .HCl and HF do not react.HBr makes sulfur dioxide.HI makes
hydrogen sulfide, H2S
◍ Reaction of hydrogen iodide with concentrated sulfuric acid?.
Answer: 8HI (aq) + H2SO4 (aq) ---> H2S (g) + 4H2O (l) + 4I2 (s)
◍ What are primary, secondary and tertiary alcohols?.
Answer: Primary: 1 other carbon attached to carbon atom to which -OH
group is bondedSecondary: 2 other carbonsTertiary: 3 other carbons
◍ Product of oxidising a primary alcohol?.
Answer: Initial product is aldehyde, which can be oxidised to a carboxylic
acid in excess oxidising agent and under reflux
◍ Product of Oxidising a Secondary Alcohol under relfux?.
Answer: Ketone
◍ Explain the colour changes when oxidising alcohols?.
Answer: .Acidified potassium dichromate can oxidise -OH
group.Primary/Secondary = orange dichromate ion Cr2O7 2- is reduced to
green chromate ion Cr3+.Tertiary = remains orange as Cr2O2 2- not
reduced
◍ What is refluxing?.
Answer: Way of safely heating volatile/flammable liquids. Liquid boils with
a vertically mounted condenser so vapour condenses and returns to reaction
mixture
◍ What is a carbonyl compound?.
Answer: Any compound that contain a carbonyl group C=O (Aldehydes or
ketones)
◍ What is the difference between an aldehyde and a ketone?.
FUNDAMENTALS OF CHEMISTRY
COMPREHENSIVE STUDY GUIDE 2026 FULL
QUESTIONS AND SOLUTIONS GRADED A+
◍ How does a substitution reaction make haloaklanes?.
Answer: -Presence of strong acid-H+ adds to a lone pair on O atom of
alcohol-C atom bonded to O now has higher partial positive charge-C atom
attacked by halide ion (nucleophile)-Products are haloalakne and water
◍ Reactivity trend of haloalkanes?.
Answer: More reactive down group 7 as weaker bond enthalpy due to outer
electrons being further from nucleus, not affected by bond polarity
◍ What is core charge?.
Answer: The core charge of an atom is a measure of the attractive force felt
by the valence shell electrons towards the nucleus. Calculated as total proton
charge - total inner electron charge
◍ What is activation energy?.
Answer: The energy with which a pair of molecules must collide in order to
react
◍ Equation for atom economy?.
Answer: Atom economy = Relative formula mass of desired products /
Relative formula mass of all reactants x 100
◍ What is a co-product?.
Answer: A valuable substance that is produced as well as the intended
product as a result of the reaction that produce the intended product
◍ How is HCl often made as a co-product?.
, Answer: Co-product of chlorination of organic compounds
◍ Which halide is the best reducing agent?.
Answer: Iodide
◍ How to make hydrogen fluoride/chloride?.
Answer: .React NaF/Cl with conc H2SO4 to make HF/Cl gas.You will see
white fumes of HCl .Not redox
◍ Why can't you make make hydrogen bromide/iodide by reacting sulfuric
acid with sodium bromide/iodide?.
Answer: .Br/I are too strong of reducing agents.Br/I reduce sulfuric aid to
sulfur dioxide.Product will a mix of hydrogen Br/I gas, sulfur dioxide and
Br/I vapour
◍ Ionic equation how bromide from HBr reduces sulfuric acid?.
Answer: 2H+ + 2Br- + H2SO4 --> SO2 + Br2 + 2H20
◍ What happens when sodium bromide reacts with concentrated sulfuric
acid?.
Answer: -Initially HBr and NaHSO4 formed-Then Br- reduces sulfuric acid
to sulfur dioxide, and produces bromine and water
◍ How can you produce hydrogen iodide/bromine?.
Answer: React sodium iodide/bromide with concentrated phosphoric acid, as
it is not so easily reduced as sulfuric acid
◍ Explain the thermal stability trend of the hydrogen halides.
Answer: Hydrogen halides get less thermally stable down the group because
bond H-Halide bond strength decreases
◍ Acidity of hydrogen halides.
Answer: HCl, HBr, and HI form stronger acids than HF, in solution, because
they dissociate into their ionse.g HCl(aq) -> H+(aq) + Cl-(aq)or H20(l) +
HCl(aq) -> H3O+(aq) + Cl-(aq)
◍ What reaction takes place between ammonia and hydrogen halides and how
to tell if it has occured?.
, Answer: .H-halides react with ammonia to make salts egNH3 (g) + HCl (g)
--> NH4Cl (g).Glass rod dipped in conc ammonia solution placed in
H-halide, white cloud of ammonium halide made
◍ How do solid hydrogen halides react with sulfuric acid?.
Answer: .HCl and HF do not react.HBr makes sulfur dioxide.HI makes
hydrogen sulfide, H2S
◍ Reaction of hydrogen iodide with concentrated sulfuric acid?.
Answer: 8HI (aq) + H2SO4 (aq) ---> H2S (g) + 4H2O (l) + 4I2 (s)
◍ What are primary, secondary and tertiary alcohols?.
Answer: Primary: 1 other carbon attached to carbon atom to which -OH
group is bondedSecondary: 2 other carbonsTertiary: 3 other carbons
◍ Product of oxidising a primary alcohol?.
Answer: Initial product is aldehyde, which can be oxidised to a carboxylic
acid in excess oxidising agent and under reflux
◍ Product of Oxidising a Secondary Alcohol under relfux?.
Answer: Ketone
◍ Explain the colour changes when oxidising alcohols?.
Answer: .Acidified potassium dichromate can oxidise -OH
group.Primary/Secondary = orange dichromate ion Cr2O7 2- is reduced to
green chromate ion Cr3+.Tertiary = remains orange as Cr2O2 2- not
reduced
◍ What is refluxing?.
Answer: Way of safely heating volatile/flammable liquids. Liquid boils with
a vertically mounted condenser so vapour condenses and returns to reaction
mixture
◍ What is a carbonyl compound?.
Answer: Any compound that contain a carbonyl group C=O (Aldehydes or
ketones)
◍ What is the difference between an aldehyde and a ketone?.
