The metal that does not react with dilute hydrochloric acid is (d) copper.
Explanation: When more reactive metals like magnesium, aluminium, and iron react with dilute hydrochloric acid, they displace hydrogen gas, forming a salt. However, copper is less reactive than hydrogen, so it cannot displace it from the acid, and therefore does not produce hydrogen gas.
Key points:
Reactivity series:
The order of reactivity of metals determines which ones can displace hydrogen from an acid.
Hydrogen gas production:
When a more reactive metal reacts with an acid, it displaces hydrogen gas, forming a salt.