The molecular weight of a gas that has a density of 7.10 g/L at 25.0 C and 1.00 atm pressure is g/mol. A) 6.85× 10-2
B) 14.6
C) 28.0
D) 174

D) 174 g/mol

Explanation:

Step 1: Given and required data

Step 2: Convert "T" to Kelvin

We will use the following expression.

K = °C + 273.15

K = 25.0°C + 273.15

K = 298.2 K

Step 3: Calculate the molecular weight (M) of the gas

We will use the following expression derived from the ideal gas equation.

ρ = P × M / R × T

M = ρ × R × T / P

M = 7.10 g/L × (0.0821 atm.L/mol.K) × 298.2 K / 1.00 atm

M = 174 g/mol