Question

Air contains about $0.03\%$ of carbon dioxide. Calculate its concentration in parts per million units.
A) $300$
B) $150$
C) $600$
D) $3$

Answer 1

We all know that air surrounds us everywhere. First, the air was thought to be a pure substance but later it was found to be a mixture of many gases. The composition of air is not constant; it changes from place to place. For example: in polluted areas, carbon dioxide is very high over there so air contains a higher percentage of carbon dioxide.

Complete step by step answer:
In order to calculate the parts per million, we can use the below formula,
$ppm = \dfrac{{{\text{Mass of solute}}}}{{{\text{Mass of solution}}}} \times {10^6}$
It is give that the mass of $C{O_2}$ is $0.03g$
Let us assume the mass of air as $100g$
$ppm = \dfrac{{0.03}}{{100}} \times {10^6} = 300$

So, the correct answer is Option A.

Note: Let us, discuss some main components of air.
Water vapor:Water in oceans and rivers evaporates and escapes into the air during summer season.. Thus water vapor is one of the components of the air and it occupies less percentage of earth’s atmosphere.
Oxygen:Air contains oxygen which supports combustion and oxygen is the one of the major components of air. Air contains $21\%$ oxygen.
Nitrogen: Air contains incombustible gases which mean gases which don’t support combustion. Nitrogen is the most abundant gas and it occupies nearly $78\%$ of earth’s atmosphere.
Carbon dioxide: Carbon dioxide is formed by respiration by plants and animals or by burning the fuel. Nearly, $0.038\%$ of the earth’s atmosphere is occupied by carbon dioxide.
Smoke and dust particles: Due to the burning of fuels,smoke is present in our atmosphere and it occupancy differs from place to place. It’s a mix of gases and it’s harmful and dust particles also are present in our atmosphere but $1\%$ of earth’s atmosphere is occupied by smoke and mud particles.