Chemistry 5070 · O Level · Identification of ions and gases
Identification of ions and gases — practice question
Pick one compound from the list below to answer the questions.
NH$_4$Cl
BaSO$_4$
KI
K$_2$SO$_3$
Mg(NO$_3$)$_2$
NaOCOCH$_3$
Na$_2$CO$_3$
Na$_3$PO$_4$
ZnSO$_4$
Any compound may be used once, more than once, or not used at all.
State which compound:
(a)[1]
it reacts with dilute nitric acid to produce a gas that makes limewater go milky.
(b)[1]
it reacts with warm aqueous sodium hydroxide to produce a gas that turns damp red litmus paper blue.
(c)[1]
it reacts with dilute hydrochloric acid to release a gas that decolourises acidified potassium manganate(VII).
(d)[1]
it is formed by a precipitation reaction.
(e)[1]
it contains an anion with a charge of $-3$.
(f)[1]
it is used to test for an oxidising agent.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The answer is Na₂CO₃.” …