What is the aim of this practical investigation? Formulate an investigative question for this practical investigation. State the hypothesis. Identify the variables. Copy and complete the table of resu

Here are the answers to your questions:

1. What is the aim of this practical investigation? The aim is to investigate the acid-base properties of vinegar and bicarbonate of soda, and to observe the reaction that occurs when they are mixed.

2. Formulate an investigative question for this practical investigation. How does mixing vinegar and bicarbonate of soda affect the acid-base nature of the resulting solution?

3. State the hypothesis. If vinegar (an acid) and bicarbonate of soda (a base) are mixed, then they will react in a neutralization reaction, resulting in a solution that is closer to neutral.

4. Identify the following variables:

   • 4.1 Dependent variable: The colour change observed (using an indicator) or the acid-base nature (acid, base, or neutral) of the substances.
   • 4.2 Independent variable: The type of substance being tested (vinegar, bicarbonate of soda, or the mixture).
   • 4.3 Controlled variable: The volume of substances used, the type of indicator used, and the temperature of the experiment.

5. Copy and complete the following table of results.

Test tube	Colour change (e.g., with universal indicator)	Acid, Base or Neutral
T1: Vinegar	Red/Orange	Acid
T2: Bicarbonate of soda	Blue/Green	Base
Solution of vinegar & bicarbonate of soda	Green/Yellow	Neutral/Slightly Acidic

6. What conclusion can be reached regarding the reaction of vinegar and bicarbonate of soda? Vinegar (acetic acid) reacts with bicarbonate of soda (sodium bicarbonate, a base) in an acid-base neutralization reaction. This reaction produces carbon dioxide gas, water, and a salt.

7. Discuss the safety precautions when using acids and bases. When using acids and bases, it is important to wear safety goggles to protect the eyes, avoid direct skin contact, and wash hands thoroughly after handling. Any spills should be cleaned up immediately and properly.

8. Balance the following chemical equation: The given equation is already balanced.

   $$\boxed{\text{NaOH}_{(\text{aq})} + \text{HCl}_{(\text{aq})} \rightarrow \text{NaCl}_{(\text{s})} + \text{H}_2\text{O}_{(\text{l})}}$$

9. When you are stung by a bee, an acid is injected into the skin, causing a burning sensation. Why would bicarbonate of soda help to calm the burning sensation after the bee sting? Bicarbonate of soda is a mild base. When applied to a bee sting, it neutralizes the acidic venom injected by the bee, which helps to reduce the burning sensation and pain.