Zinc reacts with dilute sulphuric(VI) acid to form a Cloze (1): JXUwMDJiJXUwMDEyJXUwMDBkJXUwMDE4 and produce hydrogen gas.

When the acid comes into contact with the Cloze (2): JXUwMDM1JXUwMDA4JXUwMDExJXUwMDE1JXUwMDBk , there is rapid effervescence/ bubbles /fizzing are produced and a Cloze (3): JXUwMDNiJXUwMDBjJXUwMDAzJXUwMDAzJXUwMDFhJXUwMDA3JXUwMDFlJXUwMDA5JXUwMDE2JXUw MDAw gas is produced that is collected:

(i) over water because it is Cloze (4): JXUwMDMxJXUwMDA3JXUwMDFkJXUwMDFjJXUwMDAzJXUwMDE5JXUwMDE3JXUwMDBlJXUwMDA5 in water

(ii)through downward displacement of air/upward delivery because it is Cloze (5): JXUwMDM0JXUwMDA5JXUwMDE2JXUwMDAw dense than air.

The first gas jar is impure.

It contains air that was present in the apparatus.

Cloze (6): JXUwMDFiJXUwMDJjJXUwMDFmJXUwMDAwJXUwMDE1JXUwMDE3JXUwMDVhJXUwMDYxJXUwMDAwJXUw MDYwJXUwMDVhJXUwMDA2JXUwMDE5JXUwMDFjJXUwMDE4JXUwMDA5JXUwMDE1JXUwMDEx solution act as catalyst