Q. Consider the following comparisons of Washing Soda and Baking Soda:
- Washing Soda has a molecular weight more than Baking Soda
- Washing Soda has a higher pH level than Baking Soda
- Washing Soda dissolves in water more quickly than Baking Soda
Which among the above is / are correct statements?
Answer:
Only 1 & 2
Notes:
- Washing Soda has a molecular weight more than Baking Soda: This statement is correct. Washing Soda (sodium carbonate, Na2CO3) has a higher molecular weight than Baking Soda (sodium bicarbonate, NaHCO3). The molecular weight of an element or compound is the sum of the atomic weights of its constituent atoms. In Washing Soda, you have two sodium (Na) atoms, one carbon (C) atom, and three oxygen (O) atoms, while Baking Soda consists of one sodium atom, one hydrogen atom, one carbon atom, and three oxygen atoms. The additional sodium atom in Washing Soda contributes to its higher molecular weight.
- Washing Soda has a higher pH level than Baking Soda: This statement is correct as well. Washing Soda (sodium carbonate) is more alkaline than Baking Soda (sodium bicarbonate). pH measures the acidity or alkalinity of a substance on a scale of 0 to 14, with lower values indicating acidity, higher values indicating alkalinity, and 7 being neutral. Washing Soda has a pH level around 11, making it quite alkaline. Baking Soda, on the other hand, has a pH level around 8.3, which is still basic but less alkaline than Washing Soda.
- Washing Soda dissolves in water more quickly than Baking Soda: This statement is incorrect. In reality, Baking Soda (sodium bicarbonate, NaHCO3) tends to dissolve in water more quickly than Washing Soda (sodium carbonate, Na2CO3). Baking Soda has higher water solubility due to its chemical composition. When Baking Soda comes into contact with water, it readily releases carbon dioxide gas and forms a solution, which is why it's often used in baking recipes to help baked goods rise.