Baking powder contains baking soda, NaHCO3, and an acidic substance such as sodium alum, NaAl(SO4)2 ~ 12 H2O. These components react in an aqueous medium to produce CO2 gas, which “raises” the dough. Write a balanced net ionic equation for the reaction.

Verified step by step guidance

Identify the reactants in the reaction: baking soda (NaHCO_3) and sodium alum (NaAl(SO_4)_2 ~ 12 H_2O).

Recognize that in an aqueous solution, these compounds dissociate into their respective ions: Na^+, HCO_3^-, Na^+, Al^3+, SO_4^2-, and H_2O.

Determine the primary reaction: HCO_3^- (bicarbonate ion) reacts with H^+ (from the acidic component) to form CO_2 (gas) and H_2O (water).

Write the molecular equation for the reaction: NaHCO_3 + NaAl(SO_4)_2 ~ 12 H_2O → CO_2 + H_2O + other products.

Convert the molecular equation to the net ionic equation by removing spectator ions, focusing on the formation of CO_2 from HCO_3^- and H^+.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Acid-Base Reactions

Acid-base reactions involve the transfer of protons (H+) between reactants. In the case of baking powder, the acidic component reacts with baking soda (sodium bicarbonate) to produce carbon dioxide gas. Understanding the nature of acids and bases, including their dissociation in water, is crucial for writing balanced equations.

Net Ionic Equations

A net ionic equation represents the actual chemical species that participate in a reaction, omitting spectator ions that do not change during the reaction. To write a net ionic equation, one must first identify the soluble ionic compounds and their dissociated ions in solution, then eliminate the spectator ions to focus on the ions that form the products.

Gas Evolution Reactions

Gas evolution reactions occur when a chemical reaction produces a gas as one of the products. In the context of baking powder, the reaction between sodium bicarbonate and an acid generates carbon dioxide gas, which is responsible for the leavening effect in baking. Recognizing the formation of gases is essential for understanding the overall reaction and its implications in cooking.