The pH of Sodium Carbonate in Water

by

Sodium carbonate, also known as washing soda, has a pH value between 11 and 12 when dissolved in water. This is due to the formation of carbonate ions ($CO_3^{2 – }$) in the solution, which are basic and increase the amount of hydroxide ions ($OH^-$), leading to a higher pH value.

Understanding the pH of Sodium Carbonate in Water

When sodium carbonate is added to water, it dissociates into sodium ions ($N{a^ + }$) and carbonate ions ($CO_3^{2 – }$). The carbonate ions then react with water to form bicarbonate ions ($HCO_3^ – $) and hydroxide ions ($OH^-$), which increase the pH of the solution.

The pH value of a sodium carbonate solution depends on its concentration. For example:

Sodium Carbonate Concentration pH Value
1 gram per liter of water 11.37
5 grams per liter of water 11.58

Contaminants or chemicals that may be present in a sodium carbonate solution can also affect its pH value. For instance, impurities such as sodium bicarbonate or sodium hydroxide can lower the pH value, while acids can decrease the pH value further.

Balancing the pH of Sodium Carbonate Solutions

PH of sodium carbonate in waterImage source: OpenStax College

To balance the pH of a sodium carbonate solution, one can add an acid or a base to neutralize the excess hydroxide ions. For example, adding acetic acid (${CH_3}COOH$) or citric acid (${C_6}H_8O_7$) can help lower the pH value, while adding sodium hydroxide ($NaOH$) can raise the pH value.

Using Sodium Carbonate as a Home Remedy

Sodium carbonate can be used as a natural cleaner and water softener. However, it is crucial to use it in moderation, as high concentrations can be harmful to the skin and eyes. It is also recommended to wear gloves and protective eyewear when handling sodium carbonate.

See also  The pH of Tap Water in San Francisco, USA: Understanding the Alkalinity and Contaminants

Conclusion

In summary, the pH value of sodium carbonate in water is between 11 and 12, and it depends on the concentration of the solution. Contaminants or chemicals present in the solution can affect its pH value, and it is essential to balance the pH by adding an acid or a base as needed. Sodium carbonate can be used as a natural cleaner and water softener, but it should be used with caution and in moderation.

References: