Question

What volume of `20%(w/w)` `"hydrochloric acid"` are need to oxidize a mass of `130*g` `"zinc metal"`?

Answer 1

`Zn(s) +2HCl(aq) rarr ZnCl_2(aq) + H_2(g)uarr`

Explanation:

Now it is a fact that `20%(w/w)` `HCl` has a molar concentration of `6.0*mol*L^-1`. To calculate this you should have been given more details in the question.

We require a TWICE molar quantity with respect to the moles of zinc.

`"Moles of zinc"=(130*g)/(65.4*g*mol^-1)=2.0*mol`

And thus we need `1/3*L` `HCl(aq)` for stoichiometric equivalence.