Which of the following has the chemical name as sodium hydrogen carbonate?

Baking soda

The correct answer is option 2. Baking soda.

Sodium hydrogen carbonate, chemically represented as NaHCO₃, is commonly known as baking soda. Here's an explanation:

1. Baking Powder:

Baking powder often contains sodium hydrogen carbonate (baking soda) as one of its components, along with an acid (usually cream of tartar) and a starch or another filler.

Baking powder serves a similar purpose in baking by providing the necessary leavening action, but it includes both the alkaline component (baking soda) and the acidic component in a balanced ratio.

2. Baking Soda (Sodium Hydrogen Carbonate):

Sodium hydrogen carbonate, NaHCO₃, is a white crystalline powder.

It is commonly used in baking as a leavening agent. When combined with an acid (like vinegar or buttermilk) in a recipe, it produces carbon dioxide gas, which causes the dough or batter to rise and become light and fluffy.

3. Washing Soda:

Washing soda, or sodium carbonate (Na₂CO₃), is a different compound. It is used for various cleaning purposes, such as laundry and household cleaning, due to its alkaline nature.

4. Plaster of Paris:

Plaster of Paris is calcium sulfate hemihydrate (CaSO₄.5H₂O), a compound used in construction and for making casts and molds. It is not related to sodium hydrogen carbonate.

So, among the options, only Baking Soda (option 2) corresponds to the chemical name sodium hydrogen carbonate.