Question

Q6. John heats up 700ml of chlorine gas from 20°C to 110°C at 1520 mm Hg. What is the final pressure of the gas when the final volume is 450ml at 0°C? (3mks)​

Answer 1

To solve this problem, we can use the combined gas law, which states that the ratio of the product of pressure and volume to the absolute temperature is constant for a given amount of gas.

The combined gas law equation is:
(P1V1) / T1 = (P2V2) / T2

Where:
P1 = initial pressure
V1 = initial volume
T1 = initial temperature (in Kelvin)
P2 = final pressure
V2 = final volume
T2 = final temperature (in Kelvin)

First, we need to convert the temperatures from Celsius to Kelvin:
Initial temperature T1 = 20°C + 273 = 293K
Final temperature T2 = 0°C + 273 = 273K

Now we can plug in the values into the combined gas law equation:
(1520 mmHg * 700 mL) / 293K = (P2 * 450 mL) / 273K

Solving for P2:
(1064000 mmHg mL) / 293 = (P2 * 450) / 273
P2 = (1064000 * 450) / (293 * 273)
P2 = 68940000 / 79809
P2 ≈ 863.95 mmHg

Therefore, the final pressure of the gas when the final volume is 450 mL at 0°C is approximately 863.95 mmHg.