Question

Use Boyle’s Law to solve for the missing value in each of the following:
a, P1 = 350.0 torr, V1= 200 ml P2 = 700 torr V2=?
b, P1 =180 mmHg V1= 2.4x105 ml P2 = ? V2=1.8x103 L

Answer 1

Boyle's Law states, at constant temperature,  pV = constant => p1 * V1 = p2 * V2.

a) p1 = 350.0 torr, V1 = 200 ml; p2 = 700 torr, V2 =?

p1 * V1 = p2 * V2 => V2 = [p1 * V1] / p2 = [350.0 torr * 200 ml ] / 700 torr = 100 ml

Answer of a) 100 ml.


b) P1 = 180 mmHg; V1 = 2.4 * 10^5 ml; P2 = ?, V2 = 1.8 * 10^3 L

First, convert the two measures of volume to the same unit.

2.4 * 10^ 5 mL / 1000 = 2.4 * 10^2 L

Now use Boyle's Law p1 * V1 = p2 * V2 => p2 = [p1 * V1] / V2

p2 = 180 mmHg * 2.4 * 10 ^2 L / (1.8 * 10^3 L) = 24 mmHg

Answer of b) 24 mmHg.