Question

16. At constant temperature the pressure of a gas is inversely proportional to its volume. If
certain amount of a gas occupies a volume of 30 cc and exerts a pressure of 85 g/cm, then
find the decrease in its pressure when the same amount of gas occupies a volume of 75 cc.​

Answer 1

Answer:

If pressure is P gm/cm and volume is V cc then

P.V= constant

when P= 85 g/cm

V=30cc

then constant= P.V=85.30

when V=75 cc

then P.75=85.30

=> P= 85.30/75=34

now pressure = 34g/cm

Answer 2

Explanation:

Given:-

At constant temperature the pressure of a gas is inversely proportional to its volume. If

certain amount of a gas occupies a volume of 30 cc and exerts a pressure of 85 g/cm.

To find:-

find the decrease in its pressure when the same amount of gas occupies a volume of 75 cc.

Solution:-

The Pressure of a gas is inversely proportional to its volume at constant temperature.

Let the pressure be P and the volume of the gas be V then

P∝1/V

=>PV=k, Where k is the constant.

=>P=k/V-----(1)

or >V=k/P ---(2)

now given that

Volume =30 CC

Pressure=85 g/cm

Then PV=30×85=2550 g cm²

Now if occupied volume (V)=75 CC

then Pressure =k/V (from(1))

=>P=2550/75

=>P=102/3

=>P=34 g/cm

Therefore,Pressure=34 g/cm

Decrease in pressure =Initial pressure - New pressure

=>85-34=51 g/cm

Answer:-

The decrease in the pressure of the gas =51 g/cm