Question

The molarity of heavy water $D_{2}O$ is :[ assume,density of $D_{2}O$ is 1 g/ml]

• A. 55.55M
• B. 50.78M
• C. 48M
• D. 50M

Answer 1

The correct option is B 50.78M

Heavy water (deuterium oxide, D2O).

To calculate its molarity you need two costants. Its density at 25C and its molar mass. These are 1.0 g/cm3 and 20.0276 g/mol

Molarity = (density / molar mass ) x 1000 moles per litre

= 50.78 Molar