Zinc and hydrochloric acid react according to the reaction:
`Zn_((s))+2HCl_((aq.))rarr ZnCl_(2(aq.))+H_(2(g))`
If `0.30` mole of `Zn` are added to hydrochloric acid containing `0.52` mole `HCl`, how many moles of `H_(2)` are produced?

Explanation

`{:(,Zn_(s),+2HCl_((aq.)),rarrZnCl_(2),+H_(2(g))),("Initial moles",0.30,0.52,0,0),("Final moles",0.04,0,0,0.26):}`
`:'` Mole ration of `Zn:HCl:H_(2) is 1:2:1`
`:.` Moles of `H_(2)` formed `= 0.26`
Note that `HCl` is used completely and thus it is limiting reagent.