Question

Calculate the molar mass of a gas at 410 torr and 55°C if 206 ng occupies 0.206 uL.

a) Insufficient information provided
b) 22.4 g/mol
c) 44.8 g/mol
d) 89.6 g/mol

Answer 1

To calculate the molar mass of a gas, we can use the ideal gas law equation and plug in the given values. The molar mass of the gas is calculated to be 722.1 g/mol.

Step-by-step explanation:

To calculate the molar mass of a gas, we need to use the ideal gas law equation and plug in the given values. The ideal gas law equation is PV = nRT, where P is the pressure in atm, V is the volume in L, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

Given: pressure = 777 torr, volume = 125 mL = 0.125 L, temperature = 126°C = 399K

First, we need to convert the pressure to atm. 1 atm = 760 torr, so 777 torr is approximately 1.022 atm.

Now we can rearrange the ideal gas law equation to solve for moles (n): n = PV/RT

Substituting the values: n = (1.022 atm)(0.125 L)/(0.0821 L.atm/mol.K)(399 K) = 0.000389 moles

Finally, we can calculate the molar mass using the formula: molar mass = mass/moles

Given: mass = 0.281 g, moles = 0.000389 moles

Therefore, molar mass = 0.281 g/0.000389 moles = 722.1 g/mol

Answer: The molar mass of the gas is 722.1 g/mol.