Calcium reacts with sulfur forming calcium sulfide. what is the theoretical yield (g) of cas(s) that could be prepared from 1.6 g of ca(s) and 4.25 g of sulfur(s)? enter your answer with two decimal places. do not type units with your answer.

The balanced equation for the above reaction is;
Ca + S ---> CaS
stoichiometry of Ca to S is 1:1
Number of Ca moles - 1.6 g/ 40 g/mol = 0.04 mol
Number of S moles  - 4.25 g / 32 g/mol = 0.13 mol
since Ca to S molar ratio is 1:1, there's excess amount of S present. 
Ca is the limiting reactant.
stoichiometry of Ca to CaS is 1:1
Number of CaS moles to be formed - 0.04 mol
Therefore mass of CaS - 0.04 mol x 72 g/mol = 2.88 g
therefore theoretical yield is 2.88