Question

The molecular mass of `H_(2)SO_(4)` is 98 amu . Calculate the number of moles of each element in 294 g of `H_(2)SO_(4)` .

Answer 1

Number of moles of `H_(2)SO_(4) = (294)/(98) = 3`.
From the formula `H_(2)SO_(4)` we know that 1 molecule of `H_(2)SO_(4)` contains 2 atoms of H , 1 atoms of S and 4 atoms of O . Thus , 1 mol of `H_(2)SO_(4)` will contain 2 mol of H , 1 mol of S and 4 mol of O atoms .
Therefore , in 3 mol of `H_(2)SO_(4)` .
number of moles of H = `2 xx 3 = 6`
number of moles of O = `4 xx 3 = 12` .