Answer
find out the number of moles and use the molar ratio (numbers in front of formulas (in this case they are all 1) to determine how many moles of each product you are going to get theoretically
n=m/M is the equation to use to get moles here
30.8 gm/32.04 g/mol=0.9612 moles of the methanol and also of the formaldehyde so
0.9612 moles of the formaldehyde x molar mass (M) 30.73 g/mol= 29.54 gm which is the theoretical yield you already have the actual yield of 24.7 gm
then divide the actual by the theoretical to get the % yield which is 83.6%
Step-by-step explanation: