Question

Calculate the theoretical yield.

a. you initially weigh 0.230g of benzaldehyde to perform an aldol condensation reaction with acetone. What will be the theoretical yielf (in grams) of the product dibenzalacetone?

b. you initially weigh 0.320g of anisaldehyde to perform an aldol condensation reaction with acetone. What will be the theoretical yielf (in grams) of the product dianisalacetone?

Answer 1

benzaldehyde + acetone --> dibenzalacetone

Mw of benzaldehyde = 106.121 g/mol

MW of Acetone = 58.08

MW of dibenzalacetone = 234.29

ratio is 2:1

so

mol of benzaldehyde = mass/MW = 0.23/106.121 = 0.002167 mol of benzaldehyde

assume enough mass of acetone

so..

2:1 ratio --> benzaldehyde 0.002167 /2 = 0.0010835 mol of product

so theoretical yield = mol*MW = 0.0010835*234.29 = 0.2538 g of dibenzalacetoneexpected

b)

if m = 0.32 g anisaldehyde

ratio is also 2:1 so

MWof anisaldehyde = 136.15

MW of product = 294.4

mol = mass/MW = 0.32/136.15 = 0.002350 mol of anisaldehyde

then, since 1:2 ratio, expect --> 1/2*0.002350 = 0.001175 mol of dianisalacetoneexpected...

mass = mol*MW = 294.4 *0.001175 = 0.34592 g expected