homework please help me

Question

for the following reaction 3.19 grams of carbon tetrachloride are mixed with excess methane (CH4). The reaction yields 2.62 grams of dichloromethane (CH2Cl2)

methane (CH4) (g) + carbon tetrachloride (g) --> dichloromethane (CH2Cl2) (g)

what is the theoritical yield of dichloromethane (CCH2Cl2)? _____ grams

what is the yield for this reaction? ____ %

Answer 1

CH₄ + CCl₄ ==> 2CH₂Cl₂ ... balanced chemical reaction

xs......3.19 g........2.62 g

moles CCl₄ used = 3.19 g x 1 mole/153.8 g = 0.0207 moles

Theoretical yield of CH₂Cl₂ = 0.0207 moles CCl₄ x 2 mol CH₂Cl₂/1 mol CCl₄ = 0.0414 moles x 84.93 g/mole

= 3.516 g = 3.52 g (to 3 significant figures)

Percent yield = actual yield/theoretical yield (x100%) = 2.62 g/3.52 g (x100%) = 74.4%