Question

At N.T.P volume of a gas is changed to one third volume at constant temperature then, the new pressure will be
1. 3 atm
2. 1 atm
3. 0.5 atm
4. 0.33 atm
5.

Answer 1

Correct Answer - Option 1 : 3 atm

Correct option-1

Concept:

Kinetic theory of gases-

• The kinetic theory of gases is a theoretical model that describes-
• the molecular composition of the gas in terms of a large number of identical tiny particles called molecules. 
• Further, this theory explains that gas pressure arises due to particles colliding with each other and the walls of the container.
• The kinetic theory of gases also defines thermodynamic variables such as temperature,
• viscosity, and thermal conductivity, and all these properties are related to the microscopic phenomenon.

An ideal gas is the one that can obey-

Ideal gas equation PV = nRT

Calculation:

Let V₁ = V, given:- V₂ = V/3.

N.T.P stand for normal temperature pressure condition,

At N.T.P, P = 1atm.

From ideal gas equation,

PV = nRT.

At constant temperature, P₁V₁ = P₂V₂ = contant.

\(\Rightarrow \frac{P_{2}}{P_{1}}=\frac{V_{1}}{V_{2}}\)

\(\Rightarrow \frac{P_{2}}{P_{1}}=\frac{V}{\left ( \frac{V}{3} \right )}=3\)

\(\Rightarrow P_{2}=3P_{1}\)

\(\because P_{1}=1atm\)

\(\therefore P_{2}=3atm\)

Hence, option-1 is correct