Question

Name the compound used to test evolution of carbon dioxide gas.

Answer 1

Hint: in the given question the compound used to test the formation of carbon dioxide gas has been asked. The carbon dioxide gas is evolved with the brisk effervescence which is hearable. The test to identify the presence of carbon dioxide is very easy.

 Complete answer:
Carbon dioxide, the gas also generally known from its chemical formula that is\[C{O_2}\]
When we treat Carbon dioxide with freshly prepared lime water that is a solution of calcium hydroxide\[Ca{\left( {OH} \right)_2}\], which react and form a white precipitate which appears to be milky and form calcium carbonate,\[CaC{O_3}\]. While adding more amounts of carbon dioxide might result in the precipitate, they dissolve to form a solution which is colorless and known as calcium hydrogen carbonate.

The reaction occurs-

\[Ca{\left( {OH} \right)_2} + {\text{ }}C{O_2} \to CaC{O_3} + {\text{ }}{H_2}O\]
\[CaC{O_3} + {\text{ }}C{O_2} + {\text{ }}{H_2}O \to \;Ca{\left( {HC{O_3}} \right)_2}\]

Thus, from the above test we can conduct the test for carbon dioxide. So, when carbon dioxide is bubbled through limewater the lime water changes from colorless to milky solution.
Hence, the freshly prepared Calcium hydroxide solution which is called lime water, is used to test evolution of carbon dioxide gas.

Note: carbon dioxide gas is one of the main building blocks of all individuals as well as of ecosystems life. As it is usually present in the gaseous form, and is also a chief part of the plant and animal life cycle. Lime water Solution is prepared by mixing calcium hydroxide in distilled or tap water and shaking it vigorously for 1-2 minutes, then let it stand for 24 hours.