Question

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

Test 1: Mix a teaspoon of sodium bicarbonate into a cup of warm water to see if it dissolves.

Test 2: Mix a teaspoon of sodium bicarbonate into a cup of vinegar to see if it fizzes.

Test 3: Heat a teaspoon of sodium bicarbonate in the oven to see if its melting point is less than 400 degrees Fahrenheit.

Which statement provides the best assessment of his tests?

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

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

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

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

Answer 1

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

Step-by-step 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.