Question

What is the approximate molarity of water $\left(H_{2}O\right)$?

• A. $18M$
• B. $25M$
• C. $55M$
• D. $75M$

Answer 1

Answer: (C)

$55M$

$1000mL$ of water is equivalent to $1000gm$ of water.

Molecular weight of water is ($2$$+$$16$), that is $18g/mol$.

$1L$ of $18g$ of $H_{2}O$ is equivalent to $1M$ of $H_{2}O$

$1L$ of $1g$ of $H_{2}O$ is equivalent to $\frac{1}{18}$$M$ of $H_{2}O$

$1000ml$ or $1L$ of $1000g$ of $H_{2}O$ is equivalent to $\frac{1}{18}$$\times$$1000$$M$ of $H_{2}O$, that is $55M$ of $H_{2}O$

Option $C$ is the correct answer.