Final answer:
Vinegar, a dilute form of acetic acid, helps in removing alkaline calcium deposits by reacting with them to form soluble substances that can be easily rinsed away. When mixed with baking soda, vinegar neutralizes it, which may bring the pH of the solution closer to neutral after the reaction subsides.
Step-by-step explanation:
Vinegar, which is a dilute form of acetic acid, is an effective agent for cleaning hard surfaces and removing calcium deposits. These deposits are alkaline in nature, and the vinegar, being an acid, reacts with them to form soluble compounds. This reaction between an acid and a base is what helps in the cleaning process.
For instance, when vinegar interacts with calcium carbonate, found in lime scale, it results in the formation of water, carbon dioxide, and calcium acetate, which is water-soluble. The resultant soluble substances can then be easily rinsed away.
Acids typically lower the pH of a solution. When vinegar and baking soda are mixed, they react to neutralize each other. Vinegar, being acidic, lowers the pH, while baking soda, a base, raises it. The immediate reaction is vigorous and produces carbon dioxide gas. After the reaction is complete, the pH of the solution will typically be closer to neutral than either of the starting substances.