Answer :
When reactants are mixed and heated and liquid collects in the sidearm of the apparatus, a chemical reaction is occurring.
What is a chemical reaction?
A chemical reaction is said to occur when reactants are combined to form products. We must note that the formation of products is evidenced by;
- Appearance of a liquid
- Appearance of a gas
- Appearance of a solid
Hence, when reactants are mixed and heated and liquid collects in the sidearm of the apparatus, a chemical reaction is occurring.
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