Question

At sea level, there are approximately 2.6 × 1025 molecules m–3 of the atmosphere. There are 5.20 × 1021 molecules m–3 of one of the gases making up the atmosphere. What is the concentration of this gas as a proportion of the total number of molecules in the atmosphere, expressed in parts per million (ppm)?

Answer 1

Answer:

$200\text{ ppm}$

Explanation:

Here, we want to calculate the concentration of the gas in ppm

What we have to do here is to divide the number of molecules of the gas by the total number of molecules in the atmosphere, after which we can convert it to ppm

Mathematically, we have that as:

$\frac{5.20\text{ }\times\text{ 10}^{21}}{2.6\times10^{25}}\text{ = 0.0002}$

Now, we have to convert to ppm

To convert to ppm, we simply have to multiply the given ratio by 1,000,000

We have this as:

$0.0002\text{ }\times\text{ 1000000 = 200 ppm}$