Question

A 1.872 g sample of a gas occupied 500 ml at 300 k and 898 torr. calculate the molecular weight, in units of g/mol, of the gas.

Answer 1

To calculate the molar mass of the gas, use the ideal gas law equation to solve for the number of moles. Then, divide the mass of the gas by the number of moles to find the molar mass. In this case, the molar mass is 19.9 g/mol.

Step-by-step explanation:

To calculate the molar mass of the gas, you can use 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 ideal gas constant, and T is the temperature in Kelvin.


Rearranging the equation, you can solve for n (moles):

• n = (PV) / (RT)
  

Next, calculate the number of moles using the values given in the question:

• n = (777 torr * 125 mL) / (0.0821 L atm mol^(-1) K^(-1) * (126 + 273) K)
  
• n = 0.0141 moles
  

Finally, divide the mass of the gas by the number of moles to calculate the molar mass:

• molar mass = 0.281 g / 0.0141 moles = 19.9 g/mol