Question

A fire extinguisher has a pressure of 12 atm at 25 ∘C.What is the final pressure, in atmospheres, when the fire extinguisher is used at a temperature of 75 ∘C , if volume and amount of gas do not change?Express your answer using two significant figures.

Answer 1

Step 1

Gay-Lussac's Law states that the pressure exerted by a gas (of a given mass and kept at constant volume) varies directly with the absolute temperature of the gas.

Mathematically:

`(P1)/(T1)=(P2)/(T2)`

P1 = pressure 1

T1 = absolute temperature 1

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P2 = pressure 2

T2 = absolute temperature 2

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Step 2

Information provided:

P1 = 12 atm

T1 = 25 °C + 273 = 298 K

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P2 = unknown

T2 = 75 °C + 273 = 348 K

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Step 3

From step 1, P2 is found as follows:

P1/T1 = P2/T2

(P1/T1) x T2 = P2

(12 atm/298 K) x 348 K = 14 atm

Answer: P2 = 14 atm