Question

How many grams of sodium will produce 4.80 grams of hydrogen gas in `2"Na"+2"H"_2"O"->2"NaOH"+"H"_2`?

Answer 1

`~110g`

Explanation:

First, we need the number of moles of hydrogen gas.

`n("H"_2)=(m("H"_2))/(M_r("H"_2))=4.80/2=2.40mol`

Mole ratio of `"H"_2:"Na"` = `1:2`

So, `4.80` moles of `"Na"` are needed.

`m("Na")=n("Na")M_r("Na")=4.80*23=110.4g` of `"Na"`