Question

Marco wants to investigate the chemical properties of sodium bicarbonate, or baking soda. He plans to carry out the tests below.

Answer 1

Answer:

Only Test 2 will indicate a chemical property of sodium bicarbonate. Tests 1 and 3 will show a physical property of the substance.

Explanation:

1) In test 1 we are dissolving sodium bicarbonate and here there is no chemical change in the property of sodium bicarbonate if it dissolved so it is a pure physical process.

2) In test 2 we are reacting sodium bicarbonate with vinegar (acetic acid).

The reaction is:

$NaHCO_{3}+CH_{3}COOH--->CH_{3}COONa+H_{2}O+CO_{2}$

Due to formation of carbon dioxide it fizzes. Thus this is a chemical property of sodium bicarbonate to acts as base.

3) In test 3, we are heating and testing the melting point of sodium bicarbonate, which is again a physical property.

Answer 2

Answer is: Only Test 2 will indicate a chemical property of sodium bicarbonate. Tests 1 and 3 will show a physical property of the substance.
Solubility in water and melting point of substance are physical property. In test 2 there is chemical property (chemical reaction):
NaHCO₃ + CH₃COOH → H₂O + CO₂ + CH₃COONa.