Question

What will be the volume of a gas when
3 litres of it is cooled down from 27°C to -73°C
at constant pressure.
​

Answer 1

Given :

Initial temperature = 27 °C

Final temperature = -73 °C

Initial volume = 3 L

To Find :

Final volume of the gas.

Solution :

❖ Charles' law : Pressure remaining constant, the volume of a fixed mass of a gas is directly proportional to its absolute temperature.

Mathematically, V ∝ T

First of all we have to convert unit of temperature from °C to K$.$

We know that, 0 °C = 273 K

➛ T₁ = 27 °C = 27 + 273 = 300 K

➛ T₂ = -73 °C = -73 + 273 = 200 K

By substituting the given values;

➠ V₁ / V₂ = T₁ / T₂

➠ 3 / V₂ = 300 / 200

➠ V₂ = 3 × 2/3

➠ V₂ = 2 L

Answer 2

${ \huge{ \overbrace{ \underbrace{ \tt{ \red{ question}}}}}}$

What will be the volume of a gas when 3 litres of it is cooled down from 27°C to -73°C at constant pressure .

${ \huge{ \overbrace{ \underbrace{ \tt { \red{solution}}}}}}$

${ \rightarrow{ \tt{ \green{at \: constant \: pressure}}}}$

${ \rm{ \pink{ : \implies{ \: charles \: law \: \: is \: \: applied}}}}$

The physical principle known as Charles' law states that the volume of a gas equals a constant value multiplied by its temperature as measured on the Kelvin scale (zero Kelvin corresponds to -273.15 degrees Celsius)

${ \red{ \boxed{ \boxed{ \orange{ \rm{ \frac{v1}{t1} = \frac{v2}{t2}}}}}}}$

V1 = 3 L

V2 = ?

T1 = 27°C = 27+273 = 300 K

T2 = -73°C = -73 + 273 = 200 K

${ \tt{ :\implies{ \green{ \frac{3 \: l}{300k} = \frac{v2}{200k} }}}}$

${ \underline{ \boxed{ \boxed{ \red{ \tt{ \: v2 \: = \: 2 \: l}}}}}}$