Question

Air containing moisture is trapped inside a sphere of radius of 2m. The air inside the sphere has an absolute humidity of $250g/m^3$.

What is the amount of water vapour present inside the sphere?

• A. 8000 g of water vapour
• B. 8375 g of water vapour
• C. 2000 g of water vapour
• D. 2375 g of water vapour

Answer 1

The correct option is B 8375 g of water vapour

Absoulute humidity is the actual amount of the water vapour in grams present in one cubic meter volume of air. It is expressed in in unit grams per meter cube$(g/m^3)$.
So, the volume of air present in the cylinder=$4/3{\mathrm{\pi r}}^3=\left(\right(4/3)*3.14*2*2*2)=33.5m^3$

Absoulte humidity = $250g/m^3$

Hence, the total amount of water vapour in the sphere is $250g/m^3*33.5m^3=8375g$