Calculate the number of moles and the mass of He gas present in a 2.00 L steel container if the pressure is 6.50 atm, and the temperature is 42.0 $\degree$C.

Question

Quizplus · Accepted Answer

First, we need to convert the temperature from Fahrenheit to Celsius:
T = (42.0 - 32) * 5/9 = 5.56°C
Next, we 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 gas constant, and T is the temperature in Kelvin. We need to convert the temperature to Kelvin:

T = 5.56 + 273.15 = 278.71 K

Now we can rearrange the ideal gas law equation to solve for n:

n = PV/RT

Substituting the given values:

n = (6.50 atm)(2.00 L)/(0.0821 L·atm/mol·K)(278.71 K) = 0.503 mol

Finally, we can use the molar mass of helium (4.00 g/mol) to calculate the mass of helium:

mass = n × molar mass = (0.503 mol)(4.00 g/mol) = 2.01 g

Therefore, the answer is B: 0.503 mol, 2.01 g.

Calculate the Number of Moles and the Mass of He °\degree°

Calculate the Number of Moles and the Mass of He $\degree$