Question

Calculate the mass of 1 molecule of naphthalene (C10H8 )

Answer 1

Mass of 1 molecule of Naphthalene = 10× mass of carbon + 8× mass of hydrogen
=>10×12 + 8×1=120+8= 128 g.

Answer 2

Answer: $21.25\times 10^{-23}g$

Explanation:

Molar mass of napthalene $C_{10}H_8$ = 128 g

According to Avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $(6.023\times 10^{23})$ of particles.

Thus $6.023\times 10^{23}$ molecules of napthalene weigh = 128 g

1 molecule of napthalene weigh $=\frac{128}{6.023\times 10^{23}}\times 1=21.25\times 10^{-23}g$