Question

What is the density of 2 mol of (He) at STP? (Show work and explain, please!!!)​

Answer 1

Answer:

d = 1.8 × 10⁻⁴ kg/L

Explanation:

Given data:

Moles of helium = 2 mol

Temperature and pressure = standard

Density = ?

Solution:

PV = nRT

V = nRT/ P

V = 2 mol × 0.0821 atm. L/ mol. K × 273 K / 1 atm

V = 44.8 L

Mass of helium:

Mass = number of moles  × molar mass

Mass = 2 mol × 4 g/mol

Mass = 8 g

Mass = 0.008 kg

Density;

Density = mass/ volume

d = 0.008 kg/ 44.8 L

d = 1.8 × 10⁻⁴ kg/L