An open flask containing air is heated from 300 K to 500 K. What percentage of air will be escaped to the atmosphere, if pressure is keeping constant?

Options

A. 80
B. 40
C. 60
D. 20

Answer

B

Explanation

`V_(1) = V , T_(1) = 300 K , T_(2) = 500 K , V_(2) = ?`
At constant pressure `V_(1) T_(2) = V_(2) T_(1) " " V_(2) = (V_(1) T_(2))/(T_(1)) = (V xx 500)/(300) = (5V)/(3)`
Volume of air escpaed = final volume - initial volume = `(5)/(V) - V = (2V)/(3)`
`therefore %` of air escaped = `(2V//3)/(5V//3) xx 100 = 40%`