Question

A eudiometer contains a 65.0 ml sample of a gas collected

bythe displacement of water. The water levels inside andoutside the
eudiometer are the same. The atomspheric pressureis 92.5 kPa and
the temperature is 23 degrees celsius. What volumewill the dry gas
occupy at STP? The vapor pressure of waterat 23 degrees celcius is
2.8kPa.

Answer 1

53.1 mL

Step-by-step explanation:

Let's assume an ideal gas, and at the Standard Temperature and Pressure are equal to 273 K and 101.325 kPa.

For the ideal gas law:

P1*V1/T1 = P2*V2/T2

Where P is the pressure, V is the volume, T is temperature, 1 is the initial state and 2 the final state.

At the eudiometer, there is a mixture between the gas and the water vapor, thus, the total pressure is the sum of the partial pressure of the components. The pressure of the gas is:

P1 = 92.5 - 2.8 = 89.7 kPa

T1 = 23°C + 273 = 296 K

89.7*65/296 = 101.325*V2/273

101.325V2 = 5377.45

V2 = 53.1 mL