Making predictions using the reactivity series
3 marks · NormalA teacher places a strip of an unknown metal, labelled M, into cold water. No reaction is seen.
The teacher then adds M to cold dilute hydrochloric acid. No reaction is seen, even after warming.
Explain what these results suggest about the position of metal M in the reactivity series. Give a reason for your answer.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
M is below hydrogen in the reactivity series; metals below hydrogen do not react with dilute acids to produce hydrogen gas.
Also accept: M is less reactive than hydrogen; M lies below hydrogen in the reactivity series
Common mistakes: Assuming M is above hydrogen; Not linking lack of reaction to position
Show mark scheme and worked solution
Marking points
B1 · 1 mark · States that M is below hydrogen in the reactivity series.
B2 · 1 mark · Explains metals below hydrogen do not react with dilute acids (no hydrogen gas produced).
B3 · 1 mark · Interprets both experimental results logically.
Worked solution
If M does not react with water or dilute acid (even on warming), it is less reactive than hydrogen. Metals below hydrogen in the reactivity series do not displace hydrogen from acids, so M must be below hydrogen.