Question

A 2.00 l mixture of helium, nitrogen and neon has a total pressure of 615 mmhg at a temperature of 255 k. If the partial pressure of helium is 101 mmhg and the partial pressure of nitrogen is 251 mmhg, what mass of neon is present in the mixture?

Answer 1

To find the mass of neon in the mixture, we can use Dalton's law of partial pressure and the ideal gas law. First, we calculate the partial pressure of neon by subtracting the partial pressures of helium and nitrogen from the total pressure. Then, we use the ideal gas law to find the number of moles of neon in the mixture. Finally, we multiply the number of moles by the molar mass of neon to calculate the mass. Mass of Neon= 0.105g

Step-by-step explanation:

To determine the mass of neon present in the mixture, we need to use the concept of Dalton's law of partial pressure. According to Dalton's law, the total pressure of a gas mixture is equal to the sum of the partial pressures of each gas component.

In this case, we are given the partial pressures of helium and nitrogen, and we need to find the partial pressure of neon. Since the total pressure of the mixture is 615 mmHg and the partial pressures of helium and nitrogen are 101 mmHg and 251 mmHg respectively, the partial pressure of neon can be calculated by subtracting the sum of the partial pressures of helium and nitrogen from the total pressure.

Partial pressure of neon = Total pressure - (Partial pressure of helium + Partial pressure of nitrogen)

Partial pressure of neon = 615 mmHg - (101 mmHg + 251 mmHg) = 263 mmHg

Now that we have the partial pressure of neon, we can use the ideal gas law to find the number of moles of neon in the mixture. The ideal gas law is given by PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

We are given the temperature of the mixture as 255 K and the total pressure as 615 mmHg. We can convert the pressure to atm by dividing it by 760 mmHg/atm. Plugging in the values into the ideal gas law equation, we can solve for the number of moles of neon:

n = (Partial pressure of neon) * (Volume) / (Total pressure * R * T)

n = (263 mmHg * 2.00 L) / (615 mmHg * (0.0821 L*atm/mol*K) * 255 K) = 0.00525 mol

Finally, we can find the mass of neon by multiplying the number of moles by the molar mass of neon. The molar mass of neon is 20.18 g/mol. Let's calculate the mass:

Mass of neon = (Number of moles) * (Molar mass of neon)

Mass of neon = 0.00525 mol * 20.18 g/mol = 0.105 g