Question

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

A. 100 mL
B. 50mL
C. 75.5mL
D. 112.5 mL

Answer 1

I would subtract 300 to 200 and I got 100

Answer 2

The final volume of the gas is 112.5 mL.

Step-by-step explanation:

It is given that,

Initial volume of the gas,
`V_1=75\ mL`

Initial pressure,
`P_1=300\ kPa`

Final pressure,
`P_2=200\ kPa`

We need to find the final volume of the gas. It can be calculated using the Boyle's law as :

p v = constant

or

`(P_1)/(P_2)=(V_2)/(V_1)`, V₂ is the final volume of the gas

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

`V_2=(300\ kPa)/(200\ kPa)* 75\ mL`

`V_2=112.5\ mL`

So, the final volume of the gas is 112.5 mL. Hence, this is the required solution.