Question

an air filled balloon has a volume of 125 L at760 mm Hg and 25 degree Celsius. what will be its volume when the pressure is 670 mm Hg and temperature 18 degree Celsius​

Answer 1

When the pressure is 670 mm Hg and temperature 18 degree Celsius, its volume will be 138.42 L.

Explanation:

According to the Combined Gas Law, we have

$\frac{P1V1}{T1}$ = $\frac{P2V2}{T2}$

Where the given values base on the question are,

P1 = initial pressure = 760 mmHg = 1 atm

V1 = initial volume = 125 L

T1 = initial temperature = 25℃ = 25 + 273 K = 298 K

P2 = final pressure = 670 mmHg = 0.881 atm ….. [∵ 1 atm = 760 mmHg]

T2 = final temperature = 18℃ = 18 + 273 K = 291 K

V2 = final volume = value need to find?

Now, substituting the given values in the combined gas law, we get

$\frac{125 * 1}{298}$ = $\frac{0.881 * V2}{291}$

⇒ 0.419 =  3.027 * 10⁻³ * V2

⇒ V2 = 0.419 / [3.027 * 10⁻³]

⇒ V2 = 0.31842 * 10³ L

⇒ V2 = 138.42 L

Thus, the required volume is 138.42 L.