The ozone molecules in the stratosphere absorb much of the ultraviolet radiation from the sun,protecting life on Earth.At a certain altitude,the temperature of the stratosphere is 240 K and the partial pressure of ozone is 1.4 × 10^-7 atm.Calculate the number of ozone molecules present in 1.00 L of atmosphere at that altitude. A)2.1 × 10¹⁵ molecules of O₃ B)4.3 × 10¹⁵ molecules of O₃ C)8.0 × 10³¹ molecules of O₃ D)1.8 × 10³² molecules of O₃

Question

Quizplus · Accepted Answer

We can use the ideal gas law to solve for the number of ozone molecules:

PV = nRT

where P is the partial pressure of ozone, V is the volume (1.00 L), n is the number of ozone molecules, R is the gas constant, and T is the temperature in Kelvin.

Rearranging the equation to solve for n:

n = (PV)/(RT)

Plugging in the given values:

n = [(1.4 × 10^-7 atm) (1.00 L)] / [(0.0821 L·atm/mol·K) (240 K)] 
n = 7.28 × 10^16

Therefore, there are 4.3 × 10^15 molecules of ozone in 1.00 L of atmosphere at that altitude.

The Ozone Molecules in the Stratosphere Absorb Much of the Ultraviolet