Question

For many purposes we can treat methane (CH) as an ideal gas at temperatures above its boiling point of -161. °C. Suppose the temperature of a sample of methane gas is raised from -13.0 °C to 17.0°C, and at the same time the pressure is changed. If the initial pressure was 0.26 kPa and the volume increased by 30.0%, what is the final pressure? Round your answer to the correct number of significant digits.

Answer 1

• 0.26kPa

Step-by-step explanation:

You can use the combined gas law:

`(P_1V_1)/(T_1)=(P_2V_2)/(T_2)`

You need to find P₂ when:

• T₁ = - 13.0 + 273.15 K = 260.15 K

• T₂ = 17.0 + 273.15 K = 290.15 K

• P₁ = 0.26 kPa

• V₂ = 1.300·V₁

Thus, clear P₂ from the equation, subsitute and compute:

`P_2=(P_1V_1T_2)/(V_2T_1)`

`P_2=(0.26kPa\cdot V_1\cdot 290.15K)/(1.300V_1\cdot 260.15K)`

P₂ = 0.26kPa ← answer

Since the factor P₁ has two significant figures, the result is limited to two significant figures.