A given mass of gas has a pressure of 80 Nm¯² at a temperature of 47°C. If the temperature is reduced to 27°C with volume remaining constant; the new pressure is?

A. 46.0 Nm⁻²
B. 75.0 Nm⁻²
C. 80.0 Nm⁻²
D. 85.3 Nm⁻²

Correct Answer:

Option B = 75.0 Nm⁻²

Explanation

Using P₁T₁=P₂T₂

P₁ = 80Nm^-2
T₁ = 47 + 273 = 320k
T₂ = 27 + 273 = 300k
P₂?

∴ = P₂ = ^P1T2/_T1

= 80×300/320 = 75. Nm⁻²