Question

What is the pH of Baking Soda and Vinegar?

Answer 1

Classification of solutions on basis of their pH

1. pH is a negative log of hydrogen ions. The pH value of any solution can be determined in aqueous or liquid form only.
2. The pH of any solution cannot be determined in solid or dry form it requires dissociation of ions as well. Thus, an aqueous solution is needed to obtain its pH value.
3. The pH of acids is less than 7.
4. The pH of bases is more than 7.
5. The pH of neutral solutions is 7 which is neutral.
6. The pH scale of any solution ranges from 0 to 14 where the pH value of 7 represents the neutral nature and 0 to 7 represents the acidic nature and 7 to 14 represents the basicity of the solution.
7. Depending on the values of pH we can further classify the solution as strongly and weakly acidic and basic.

The pH of Baking soda

1. When Carbonic acid${\mathrm{H}}_2{\mathrm{CO}}_3$ and Sodium hydroxide$\mathrm{NaOH}$ is reacted they form Baking soda ${\mathrm{NaHCO}}_3$which is salt and water. This type of reaction is known as a neutralization reaction. ${\mathrm{H}}_2{\mathrm{CO}}_3\left(\mathrm{g}\right)+\mathrm{NaOH}\left(\mathrm{aq}\right)\to {\mathrm{NaHCO}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$
2. This is a basic salt and the pH lies in the range of 8-9.
3. Higher temperature shifts the equation to the right, slightly increasing the carbonate to bicarbonate ratio.
4. At the same time, the acid (H⁺) concentration increases slightly which causes a slight drop in pH.
5. This means that a warmer solution can have better-buffering capacity despite a lower pH.

The pH of Vinegar

1. Vinegar or Acetic Acid (${\mathrm{CH}}_3\mathrm{COOH}$) is a weak acid.
2. The pH of Vinegar is approximately 3.
3. Increasing the temperature also increases the molecular vibration of concentration of [H+] ion for this decreases the tendency of forming hydrogen bonds, thus leading to a reduction in pH.