Question

Give one standard test for carbon dioxide. Also write the equation involved. Is it a physical change or chemical change?

Answer 1

The standard test for CO2 is passing through lime water. The reactions involved are:
CO2+Ca(OH)2------------>CaCO3+H2O

Answer 2

ANSWER:

For the standard test of carbon dioxide, pass the carbon dioxide gas through the lime water. As a result of carbon dioxide gas it turns the lime water which is milky white in appearance.

EXPLANATION:

The reaction involved is:

Carbon dioxide gas combines with calcium carbonate (lime water) to form, calcium carbonate and water.

$C O_{2}+C a(O H)_{2} \rightarrow C a C O_{3}+H_{2} O\right.$

It is a chemical change because the substance has transformed into a new substance, having different chemical composition.