percent yield for chemistry

Question

when 100 kg sand are processed with carbon and 51.4 k sic are recovered. what is the percent yield of sic

Answer 1

Sand is mostly SiO2 (molar mass 60 g/mol), therefore 100 kg (100,000 g) sand contain (100,000/60) moles of Si.

On other hand 51.4 kg of SiC (molar mass 40 g/mol) contain (51,400/40) moles of Si.

Hence %yield = (51,400/40) / (100,000/60) x 100% =

(51,400 x 60 x 100%) / (40 x 100,000) = 77.1%