Question

What's the final volume of a gas with an initial volume of 75 mL if the pressure decreases from 300 kPa to 200 kPa?

A. 112.5 mL
B. 75.5 mL
C. 100.0 mL
D. 50.0 mL

Answer 1

The correct answer is A, because P1V1=P2V2...300x75=200xX...22500=200X so X=22500÷200=112.5ML    ..

Answer 2

Option (a) is correct.

The final volume of a gas is 112.5 mL.

Explanation:

Given : Initial volume of gas = 75 mL

And the pressure decreases from 300 kPa to 200 kPa.

We have to determine the final volume of a gas.

Using Boyle's Law:

The Volume of an ideal gas is inversely proportional to its pressure.

That is

`(V_1)/(V_2)=(P_2)/(P_1)`

That is
`P_1\cdot V_1=P_2\cdot V_2`

Given:
`V_1=75` ml

`P_1=300` KPa

and
`P_2=200` KPa

Let
`V_2=x` ml

Thus,
`300\cdot 75=200\cdot x`

Divide both side by 200, we have,

`(300\cdot 75)/(200)= x`

Simplify, we have,

`V_2=112.5` ml

Thus, The final volume of a gas is 112.5 mL.