Question

The mole fraction of argon in dry air near sea level is 1.821 × 10⁻⁵, where the molar mass of argon is 39.948.

The concentration of argon in the atmosphere is ________%.
a. 0.00182%
b. 0.0182%
c. 1.82%
d. 18.2%

Answer 1

To find the concentration of argon in the atmosphere, the mole fraction (1.821 × 10⁻⁵) is multiplied by 100%, resulting in a concentration of 0.00182%.

Step-by-step explanation:

The concentration of argon in the atmosphere can be calculated using the given mole fraction. The mole fraction of argon in dry air near sea level is given as 1.821 × 10⁻⁵. To express this mole fraction as a percentage, we simply multiply by 100%:

Mole fraction of argon × 100% = 1.821 × 10⁻⁵ × 100% = 0.001821%

Therefore, the correct answer to the student's question is (a) 0.00182%.