`N_(2)+3H_(2)rarr 2NH_(3)`
(The atomic mass of nitrogen is 14, and that of hydrogen is 1)
`"1 mole of nitrogen "(………….g)+`
`"3 moles of hydrogen "(……….g)rarr`
`"2 moles of ammonia "(……….g)`

Explanation

`N_(2)+3H_(2)rarr 2NH_(3)`
1 mole of `N_(2)=28g`
3 moles of `H_(2)=6g`
2 moles of `NH_(3)=34g`
1 mole of nitrogen `(28g)+3` moles of hydrogen `(6g)rarr2` moles of Ammonia (34g)