See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

ROH 3 CH COCl ROCOCH3 Here H is replaced by COCH3 i.e. one H of mass 1 is replaced by one COCH3 of mass 43.  Mass increased is 42.  Mass of acylated product is = 92  237 218 100   increase in mass = 218 – 92 = 126  number of OH = 126/42 = 3