Which of the following is called baking soda?

$NaHCO_3$

The correct answer is Option (2) → $NaHCO_3$

Baking soda is the common name for: Sodium Bicarbonate → Chemical formula: NaHCO₃

• Na₂CO₃ → Sodium carbonate (Washing soda)

• NaOH → Sodium hydroxide (Caustic soda)

• CaCO₃ → Calcium carbonate (Found in chalk, limestone, shells)