What is the empirical formula of a compound that is 14 g calcium, 11 g oxygen, and 0.7 g hydrogen?

A. Ca2OH2

B. Ca (OH) 2

C. CaO2H

D. CaOH

We are given with the mass of the elements. Taking a 100-gram basis, we convert the mass of the reactants to moles. Calcium is equal to 0.35 moles, oxygen is equal to 0.6875 and hydrogen is equal to 0.7 moles. We divide each number to the less amount. Hence Ca is 1, O is 1.96 and H is 2. Answer is B. Ca (OH) 2, calcium hydroxide.