Chloroform (CHCl3), an important solvent, is produced by a reaction between methane and chlorine. CH4 (g) + 3 Cl2 (g) CHCl3 (g) + 3 HCl (g) How many grams of CH4 is needed to produce 66.5 g CHCl3?

CH4 + 3Cl2 - - - > CHCl3 + 3 HCl

one molecules of CH4 reacted with 3 molecules of Cl to form one molecule of CHCl3 and 3 molecules of HCl

this implies that the ratio of CH4 to CHCl3 is 1:1

the moles of CHCl3 formed=66.5/119.5 (molar mass of CHCl3) = 0.556 moles

since ratio is 1:1 the moles of CH4 is also 0.556moles

mass=moles x molar mass

mass=0.556 x 16 (molar mass of CH4) = 8.896grams