Question

The molarity of $900\text{g}$ of water is:

• A. $50\text{M}$
• B. $55.5\text{M}$
• C. $5\text{M}$
• D. Cannot be calculated

Answer 1

The correct option is B $55.5\text{M}$

Molarity is number of moles per litre.
$900\text{g of}{H}_{2}O=\frac{900}{18}\text{moles}=50\text{moles}$
$900\text{g of}{H}_{2}O=900\text{ml of}{H}_{2}O$
$\therefore$ Molarity = $\frac{50}{900}\times 1000=55.5\text{M}$