60.6182g
first convert grams to moles. 10g Si=.357mol and 60g Cl2 = .846mol
to do this you divide the grams by the given molar mass
second you convert moles of reactants to moles of products. this is done using the mole ratio: 1 mole Si = 1 mole SiCL4 and 2 mol Cl2 = 1 mol SiCl4. The mole ratio can be found in the balanced equation.
.357mol Si = .357 mol SiCl4
.846mol Cl2 = .423 mol SiCl4
Si is the limiting reagent
.357mol SiCl4 = 60.6186g
to get this you multiply the amount of moles by the molar mass
.357mol x 169.8g/mol = 60.6186g