Question

В сосуде находится 2 моль водяного пара. Если при изотермическом уменьшении объёма в 6 раз в сосуде осталось 12 г пара, то отношение давления насыщенного пара при данной температуре к первоначальной упругости водяного пара в сосуде равно???

Answer 1

Calculation of the Pressure Ratio

To find the ratio of the pressure of the saturated vapor at the given temperature to the initial vapor pressure in the vessel, we can use the ideal gas law. The ideal gas law states that the pressure of a gas is directly proportional to the number of moles of gas and the temperature, and inversely proportional to the volume of the gas.

Given: - Initial number of moles of water vapor in the vessel = 2 mol - Final number of moles of water vapor in the vessel = 12 g (which can be converted to moles using the molar mass of water)

To calculate the final number of moles of water vapor, we need to convert the mass of water vapor to moles. The molar mass of water (H2O) is approximately 18 g/mol. Therefore, the final number of moles of water vapor is:

Final number of moles of water vapor = (12 g) / (18 g/mol) = 0.67 mol

Now, we can calculate the ratio of the pressure of the saturated vapor at the given temperature to the initial vapor pressure in the vessel.

Since the process is isothermal (constant temperature), the initial and final temperatures are the same. Therefore, the ratio of the pressures is equal to the ratio of the number of moles of water vapor:

Pressure ratio = (Final number of moles of water vapor) / (Initial number of moles of water vapor) = 0.67 mol / 2 mol = 0.335

Therefore, the ratio of the pressure of the saturated vapor at the given temperature to the initial vapor pressure in the vessel is approximately 0.335.

Please note that the above calculation assumes ideal gas behavior and neglects any non-ideal effects that may occur at high pressures or low temperatures.