Question

A certain aldehyde B is subsequent to an aldehyde A in the homologous series of aldehydes. An amount of 19 g of aldehyde B is added to 100 g of an aqueous solution containing 23 mass % of aldehyde A. Addition of AgNO₃ in ammonia solution to 2 g of the aldehydes solution results in a precipitation of 4.35 g of silver. 

Determine by calculation what aldehydes were used. 2. Give the structural formulas of the aldehydes. 

Relative atomic masses: A_r(C) = 12.01; A_r(O) = 16.00; A_r(H) = 1.01; A_r(Ag) = 107.87 

Answer 1

According to equation (1): 

M(A) = 30 g mol^-1

M(B) = 44 g mol^-1  

A = formaldehyde, methanal 

B = acetaldehyde, ethanal