Question

What is the formula unit mass of sodium chloride?

• A. 58.5
• B. 35.5
• C. 23
• D. 40

Answer 1

The correct option is A 58.5

The formula of sodium chloride is $NaCl$

Atomic weight of sodium $\left(Na\right)$ is $23g/mol$

Atomic weight of chloride $\left(Cl\right)$ is $35.45g/mol$

Therefore, the formula unit mass of sodium chloride $\left(NaCl\right)$ is $23+35.45=58.45g/mol$ which nearly equals to $58.5g/mol$

Hence, option $A$ is correct.