What is the empirical formula for the compound containing 13.5 g Ca, 10.8 g O, and 0.675 g H?

1 Answer
Dec 27, 2016

#Ca(OH)_2#

Explanation:

We divide each given mass by the atomic mass of each individual element:

#"Calcium:"# #(13.5*g)/(40.1*g*mol^-1)=0.337*mol.#

#"Oxygen:"# #(10.8*g)/(15.999*g*mol^-1)=0.675*mol.#

#"Hydrogen:"# #(0.675*g)/(1.008*g*mol^-1)=0.675*mol.#

If we divide thru by the smallest atomic quantity, we get an empirical formula of, #CaH_2O_2#, i.e. #Ca(OH)_2#.