At constant pressure, the density of a fixed mass of gas is
Answer Details
When the pressure of a gas is kept constant, the density of the gas will only be affected by changes in its temperature and volume. As the temperature of the gas increases, the density decreases, since the gas molecules move faster and take up more space. As the volume of the gas increases, the density decreases, since the same mass of gas is spread over a larger volume. Therefore, the correct option is: "inversely proportional to its temperature."