Answer
Empirical formula: $C_2H_{6}As$
Molecular formula: $C_4H_{12}As_2$
Work Step by Step
Atomic weights (g/mol):
$C: 12.011, \ H: 1.008,\ As: 74.921$
In 100 g :
C: $22.88\ g \div 12.011 \ g/mol=1.90\ mol$
H: $5.76\ g\div1.008\ g/mol=5.71\ mol$
As: $71.36\ g\div74.921\ g/mol=0.952\ mol$
Dividing all these number of moles by the smallest value (0.952) leads to the empirical formula:
$C_2H_6As$
Molar mass of the empirical formula: $104.99\ g/mol$
Molar mass of the compound: $210\ g/mol$
Ratio of the two: 2.00
Molecular formula: $C_4H_{12}As_2$
