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Gas Test – How To Prepare?

Whether you have an exam that you need to know how to gauge or are just curious, you are in the right place. In this article, we have highlighted what you need to know about gas tests.

About Gas Tests

Knowing how to identify the type of gas is an important skill to have. This is because many reactions can result in the production of different gases, which are usually colourless and odourless. Gas tests are generally done in chemistry. They focus on testing students’ knowledge of how to identify gases and conduct gas tests.

Common gases are usually tested in these exams. These include oxygen, hydrogen, and carbon dioxide. These exams may also require students to know the characteristics that certain gases will present during these tests to differentiate between gases.

How to Identify Types of Gases

The standard tests which are done to identify different types of gasses include:


The most common way to test for oxygen is to take a glowing splint and expose it to the gas in a test tube. If the splint lights up, this usually means that oxygen is present. This is because oxygen causes combustion to occur.


Testing for hydrogen consists of having a test tube of the gas and placing a burning splint in the test tube. If this causes a squeaky pop noise, this is a sign that hydrogen is present.

Carbon Dioxide

Testing for carbon dioxide involves bubbling the gas with lime water. If the limewater (calcium hydroxide) turns milky, it means that carbon dioxide is present. Limewater turns milky because it reacts with carbon dioxide and creates calcium carbonate.

Types of Questions Asked in Gas Tests

Usually, the questions asked in gas tests are about what reactions certain gases cause or what is used in the tests to identify the gases. A gas test usually follows a multiple-choice question format.

Gas tests sample questions:

1. Which gas causes a squeaky pop?

2. Which gas is present when the glowing splint reignites during a test?

3. A gas test that uses lime water is testing for which gas?

Preparation Tips for Gas Tests

  • Read over the study material – make sure that you cover all the steps that are done in different gas tests.
  • Complete practice tests – there are many practice tests to choose from online. This is the best way to make sure you are ready for your exam.
  • Watch demonstration videos – seeing different gasses being tested will make it easier to remember how these tests are conducted.

Final Thoughts

Knowing how to identify the presence of different gasses is a vital skill to have. While these tests might seem overwhelming at first, you will quickly identify other gasses once you follow the preparation tips.