Use PV = nRT to solve for n.
Then n = grams/molar mass.
A. 2.90 g of gas that occupies 0.500 L at 0 C and 1.00 atm (STP)
B. 1.48 G of gas that occupies 2.00 L at 0 C and 760 mmHg (STP)
C. 0.726g of a gas that occupies 855 mL at 1.20 atm at 18 C?
D. 2.32 G of a gas that occupies 1.23 L at 685 mmHg and 25 C?
Then n = grams/molar mass.
To calculate the number of moles, you can rearrange the equation as n = PV / RT.
Once you have the number of moles, you can calculate the molar mass by dividing the mass of the gas by the number of moles.
A. To find the molar mass of the gas with 2.90 g that occupies 0.500 L at 0 °C and 1.00 atm (STP):
First, convert the temperature from Celsius to Kelvin by adding 273.15. So, the temperature is 273.15 K.
Then, you can use the ideal gas equation: PV = nRT.
Plug in the values:
P = 1.00 atm
V = 0.500 L
R = 0.0821 L·atm/(mol·K)
T = 273.15 K
Rearrange the equation to solve for n:
n = PV / RT = (1.00 atm * 0.500 L) / (0.0821 L·atm/(mol·K) * 273.15 K)
n ≈ 0.0254 mol
Now, calculate the molar mass:
Molar mass = mass / moles = 2.90 g / 0.0254 mol
Molar mass ≈ 114 g/mol
Therefore, the molar mass of the gas in part A is approximately 114 g/mol.
You can follow a similar process to solve parts B, C, and D. Remember to convert the units to a consistent system (either all SI or all non-SI units) before performing calculations.