4 If 05 g of tertbutanol MW 7412 gmol reacts with HCI conc t

4. If 0.5 g of tert-butanol (MW 74.12 g/mol) reacts with HCI (conc.) to give 0.35 g of tert-butyl chloride (MW 92.57 g/mol), what is the percentage yield of the reaction? a),56% b) 70% c) 80% d) 178% e) none of these

Solution

Ans : a) 56%

Number of moles of tert-butanol = 0.5 / molar mass

= 0.5 / 74.12

= 0.0067 mol

1 mol of tert-butanol gives one mole of tert-butyl chloride

So 0.0067 mol of tert-butanol gives 0.0067 mol of tert-butyl chloride

Theoretical yield of tert-butyl chloride = 0.0067 x 92.57

= 0.62 g

percentage yield = (0.35 / 0.62) x 100

= 56%