Chemistry 5070 · O Level · Preparation of salts

Preparation of salts — practice question

A sample of an alloy made up of aluminium and copper is placed in hot dilute sulfuric acid. The dilute sulfuric acid reacts only with the aluminium. Hydrogen and aqueous aluminium sulfate are formed in the reaction.
(a)[2]

Construct the ionic equation, including state symbols, for aluminium reacting with dilute sulfuric acid.

(b)[2]

Describe a chemical test for aluminium ions.

(c)[2]

Aqueous aluminium sulfate is crystallised to produce hydrated aluminium sulfate, Al$_2$(SO$_4$)$_3\cdot x$H$_2$O. The relative formula mass of hydrated aluminium sulfate is 666. Calculate the value of $x$ in the formula Al$_2$(SO$_4$)$_3\cdot x$H$_2$O.

(d)[1]

State the meaning of the term alloy.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “2Al(s)+6H⁺(aq)→2Al^{3}⁺(aq)+3H₂(g)” …

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI