Question

1. a gas in a sealed, rigid steel container is heated from a temperature of 0.0 °c to 300 °c. which of the following physical properties will remain constant?

the cylinder pressure.
the intensity with which the molecules impact the walls of the cylinder.
the amount of the gas.
the average kinetic energy of the molecules.

Explanation:

Step1: Recall gas - law concepts

For a sealed, rigid container, the volume \(V\) is constant and the number of moles \(n\) of the gas is constant since it is sealed (no gas can enter or leave).

Step2: Analyze pressure

According to the ideal - gas law \(PV = nRT\), when \(V\), \(n\) are constant and \(T\) increases (\(T_1=0^{\circ}C = 273\ K\), \(T_2 = 300^{\circ}C=300 + 273=573\ K\)), pressure \(P=\frac{nR}{V}T\) will increase as \(T\) increases.

Step3: Analyze molecular impact intensity

The intensity of molecular impact on the walls is related to pressure. As pressure increases (from Step 2), the intensity of molecular impact on the walls increases.

Step4: Analyze amount of gas

Since the container is sealed, the amount of gas (number of moles \(n\)) remains constant.

Step5: Analyze average kinetic energy

The average kinetic energy of gas molecules is directly proportional to the temperature (\(\overline{KE}=\frac{3}{2}kT\)). As the temperature increases from \(0^{\circ}C\) to \(300^{\circ}C\), the average kinetic energy of the molecules increases.

Answer:

The amount of the gas.