Question

A gas collected when the temperature is 7°C and the pressure is 140 kPa has a volume of 4 L. Calculate its volume at 60 kPa and 27°C.

a) 3 L
b) 5 L
c) 6 L
d) 7 L

Answer 1

Using the Combined Gas Law and converting temperatures to Kelvin, the volume of the gas at 60 kPa and 27°C is calculated as 7 L, matching option (d).

Step-by-step explanation:

A gas collected at 7°C and 140 kPa with a volume of 4 L needs to have its volume calculated at 60 kPa and 27°C. To accomplish this, we can use the Combined Gas Law which states that the ratio of the product of pressure and volume to the temperature is constant for a fixed amount of gas, thus:

P1 · V1 / T1 = P2 · V2 / T2

First, we need to convert temperatures to Kelvin by adding 273.15:

T1 = 7 + 273.15 = 280.15 K

T2 = 27 + 273.15 = 300.15 K

Next, we plug our known values into the Combined Gas Law and solve for V2:

(140 kPa · 4 L) / 280.15 K = (60 kPa · V2) / 300.15 K

V2 = (140 kPa · 4 L · 300.15 K) / (60 kPa · 280.15 K)

V2 = 7 L

The volume of the gas at 60 kPa and 27°C is thus 7 L, which corresponds to option (d).