Which of the following are usually used for the preparation of H2 gas in laboratory?
Granulated impure Zn and dilute HCI
Pure Zn and conc. HCI
Pure Zn and conc.H2SO4
All of the above
Granulated Zn is porous and impure. rt has high surface area, high reactivity and forms Galvanic cell in dilute HCI to produce H2 gas easily.
Zn+2H+→ Zn2++H2