Answer
Mass of a $(C_{2}H_{5})_{2}O$ molecule = 12.309 g
Work Step by Step
Strategy: To calculate the mass of one molecule we should use: 1- Molar mass, that is the mass of one mole of substance 2- relationship of mole and Avogadro's number .
Molar mass $(C_{2}H_{5})_{2}O$ = 4 $\times$ AM C + 10 MA H + 1 x AM O
Molar mass $(C_{2}H_{5})_{2}O$ = 4x12.01+ 10 x 1.007+ 1 15.99
Molar mass $(C_{2}H_{5})_{2}O$ = 4x12.01+ 10 x 1.007+ 1 15.99
Molar mass $(C_{2}H_{5})_{2}O$ = 74.1 g
Mass of a $(C_{2}H_{5})_{2}O$ molecule = $\frac{molar mass_{(C_{2}H_{5})_{2}O}}{Avogadro's number}$
Mass of a $(C_{2}H_{5})_{2}O$ molecule = 12.309 g
