How would you know all the acid has reacted when adding zinc to sulfuric acid?

Answer 1

Zinc has a negative reduction potential (Eo = -0.76V) so it is favorable for zinc to be oxidized (the opposite of being reduced) under standard conditions: Zn --> Zn2+ + 2 e- Eo = +0.76V In sulfuric acid you primarily have three species present (not including the water): H+, HSO4-, and SO42-. Of these three, H+ has the highest reduction potential: 2 H+ + 2 e- --> H2 Eo = 0.00V So in the presence of H+ ions from sulfuric acid, zinc will oxide to form Zn2+: 2 H+ + Zn --> H2 + Zn2+ Eo = 0.00V + 0.76V = 0.76 V

Answer 2

You can tell that all the acid has reacted with the zinc when there are no more bubbles of gas being produced. This indicates that the chemical reaction between the zinc and sulfuric acid is complete, resulting in the formation of zinc sulfate and hydrogen gas.

Answer 3

if you were adding zinc metal to sulphuric acid, how would you know when all the acid had all reacted?