Question

What happens when dilute sulphuric acid is poured on a copper plate. Explain.

Answer 1

Copper does not react with dilute sulphuric acid. So, no reaction takes place when dilute sulphuric acid is poured on a copper plate. But when concentrated sulphuric acid is poured over copper plate, effervescence is observed. This happens because of formation of hydrogen gas.

Copper does not react with dilute sulphuric acid as its reduction potential is higher than that of hydrogen. Copper does not displace hydrogen from non-oxidizing acids like HCl or dilute H2SO4. But, concentrated sulphuric acid is an oxidizing agent.