Gas Problems: Calculating Partial Pressure of N2

How can we calculate the partial pressure of N2 in a sample of dry gas?

A 1.00 L sample of dry gas at 17°C and 756 mmHg contains 0.530 g of N2. What is the partial pressure of N2?

Calculating Partial Pressure of N2

To determine the partial pressure of N2, we need to follow these steps:

1. Calculate the number of moles of N2 in the sample.
2. Convert the temperature from Celsius to Kelvin.
3. Use the ideal gas law equation, PV = nRT, to find the partial pressure of N2.

Calculating the Partial Pressure of N2

Firstly, we need to calculate the number of moles of N2 in the sample. The molar mass of nitrogen (N2) is 28.01 g/mol. By dividing the mass of N2 in the sample (0.530 g) by the molar mass, we get approximately 0.0189 moles of N2.

Next, we convert the temperature from Celsius to Kelvin by adding 273 to 17°C, giving us 290 K.

Using the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant (0.0821 L·atm/mol·K), and T is the temperature in Kelvin, we can determine the partial pressure of N2.

Substitute the values into the equation: P = (nRT) / V. By plugging in the values (0.0189 mol * 0.0821 L·atm/mol·K * 290 K) / 1.00 L, we find that the partial pressure of N2 is approximately 0.456 atm.

Converting this value to mmHg (1 atm = 760 mmHg), we get a partial pressure of N2 of about 346 mmHg. Therefore, none of the provided options are correct.

By following these steps and calculations, we can accurately determine the partial pressure of N2 in the gas sample.