Question

The gas in a container has a pressure 300kPa at 27 C. What will the pressure be if the

temperature is lowered to -173 C?

Answer 1

The pressure will be 225 kPa.

Step-by-step explanation:

According to Charles's Law, for a gas at constant volume and amount, the pressure and temperature are directly proportional, as long as the temperature is in Kelvin. This relationship is represented by the equation: P₁ / T₁ = P₂ / T₂, where P₁ and T₁ are the initial pressure and temperature, and P₂ and T₂ are the final pressure and temperature. To solve the problem, we can use the equation rearranged as: P₂ = P₁ * (T₂ / T₁). Given that the initial pressure (P₁) is 300 kPa and the initial temperature (T₁) is 27 °C, we need to convert the temperature to Kelvin by adding 273.15 to it. The final temperature (T₂) is -173 °C, so we also need to convert it to Kelvin. Plugging these values into the equation, we get:

P₂ = 300 kPa * (273.15 K / (273.15 K + 27 °C)) = 225 kPa

The final pressure will be 225 kPa.

Answer 2

100 kPa

Step-by-step explanation:

This can be solved with one of the gases law. This law establishes that the pressure of the gas is directly proportional to its temperature: If we increase the temperature, the pressure will increase.

In this case, we decrease the temperature, so its pressure will be lower.

P₁ / T₁ = P₂ / T₂

We convert T° to Absolutes Values

27°C + 273 = 300 K

-173°C + 273 = 100 K

300 kPa / 300 K = P₂ / 100 K

(300 kPa / 300 K) . 100K = P₂

P₂ = 100 kPa

This is the Charles Gay Lussac's law.