Question

Define chemical reaction. State four observations which helps us to determine that a chemical reaction has taken place. Write one example of each observation with a balanced chemical equation

Answer 1

Answer:

Explanation:

Chemical reaction is a process in which one or more reactants are converted into products.

The product may be one or more. The chemical reaction can involve an element or a compound which leads to the formation of product or products.

The observation which may be used to show that a chemical reaction has taken place may include;

1. Change in colour- Reaction of Bromine and ethene

( Br2(l) +  C2H4⇒ CHBrCHBr)

2. formation of a precipitate- silver nitrate and NaCl

(AgNO3 (aq) + NaCl= AgCl(s) + NaNO3)

3. Temperature change

4. Change of smell