IB Chemistry HL R3.2 Electron transfer reactions questions

Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.

Question 1

Multiple choiceMedium1 mark

A piece of magnesium is added to dilute hydrochloric acid. Which equation represents the reaction?

Show answer and explanation

Answer: B. Magnesium reacts with dilute hydrochloric acid to form magnesium chloride and hydrogen gas. Magnesium chloride has the formula MgCl₂; balancing the atoms gives Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g).
A: identifies the products but leaves chlorine unbalanced by using one HCl.
C: balances the atoms but gives magnesium the wrong charge in the salt formula, writing MgCl instead of MgCl₂.
D: balances the atoms but represents the hydrogen as individual atoms rather than diatomic hydrogen, H₂.
Remember: hydrogen released in these reactions is H₂(g).

The best questions are still waiting

Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.