Use molar volume to solve the following problems at STP.

Find the volume mL occupied by 0.400 mole He.

Find the number of grams of neon contained in 10.2 L Ne gas

a. Use PV = nRT

b. I presume this is at STP. You know that 1 mole Ne gas occupies 22.4 L at STP. So how many moles is 10.2 L?

To use molar volume to solve these problems, we need to know the value of molar volume at STP, which is 22.4 liters per mole (L/mol).

Problem 1: Find the volume (in mL) occupied by 0.400 mole of He.

We can use the equation: Volume (in L) = number of moles × molar volume.

Given:
Number of moles (n) = 0.400 mole
Molar volume (V) = 22.4 L/mol

Calculating the volume:
Volume = 0.400 mol × 22.4 L/mol
Volume = 8.96 L

To convert liters to milliliters, we multiply by 1000:
Volume = 8.96 L × 1000 mL/L
Volume = 8960 mL

Therefore, 0.400 mole of He occupies 8960 mL of volume.

Problem 2: Find the number of grams of neon contained in 10.2 L of Ne gas.

To solve this problem, we will first find the number of moles of neon, and then convert it to grams using the molar mass of neon.

Given:
Volume (V) = 10.2 L
Molar volume (V) = 22.4 L/mol

Calculating the number of moles:
Number of moles = Volume / Molar volume
Number of moles = 10.2 L / 22.4 L/mol
Number of moles = 0.455 mole

The molar mass of neon (Ne) is approximately 20.18 g/mol.

Calculating the mass:
Mass = Number of moles × Molar mass
Mass = 0.455 mol × 20.18 g/mol
Mass = 9.19 g

Therefore, 10.2 L of Ne gas contains 9.19 grams of neon.