# Chemistry Class 11 NCERT Solutions: Chapter 5 States of Matter Part 5

Q: 15. Calculate the total pressure in a mixture of 8 g of Dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm^3 at 27° C. R=0.083 bar

Answer:

Given,

Mass of Dioxygen

Thus, number of moles of

Mass of dihydrogen

Thus, number of moles of

Therefore, total number of moles in the mixture

Given,

Total pressure (p) can be calculated as:

⇒

Hence, the total pressure of the mixture is 56.025 bar.

Q: 16. Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius 10 m, mass 100 kg is filled with helium at 1.66 bar at . (Density of air)

Answer: Given,

Radius of the balloon,

Thus, the volume of the displaced air is 4190.5

Given,

Density of air =

Then, mass of displaced air= 4190.5× 1.2 kg

Now, mass of helium (m) inside the balloon is given by,

Here,

V

Now, total mass of the balloon filled with helium =

Hence, pay load

Hence, the pay load of the balloon is 3811.1 kg.

Q: 17. Calculate the volume occupied by

Answer:

It is known that,

Here,

Thus, volume (V) =

Hence, the volume occupied is