Question

during a chemistry demonstration, a student added liquid hydrochloric acid, hcl, to a beaker holding powdered baking soda, nahco₃. the solution in the beaker began to bubble and fizz as carbon dioxide gas, co₂, escaped. how did combining a liquid and a solid produce a gas?
a. the atoms in the hydrochloric acid and baking soda combined, forming a product with a different state but the same properties.
b. adding the hydrochloric acid to the baking soda superheated the hydrochloric acid, causing it to change phases.
c. the atoms in the hydrochloric acid and baking soda rearranged, forming products with different properties.
d. adding the hydrochloric acid to the baking soda superheated the baking soda, causing it to change phases

Explanation:

When hydrochloric acid (\(HCl\)) reacts with baking soda (\(NaHCO_3\)), a chemical reaction occurs. In a chemical reaction, the atoms of the reactants rearrange to form new products. The reaction is \(NaHCO_3+HCl = NaCl + H_2O+CO_2\uparrow\).

• Option A: In a chemical reaction, products have different properties, not the same. So, this option is wrong.
• Option B: The reaction is a chemical reaction, not just a phase - change due to superheating of \(HCl\).
• Option C: This is correct as in a chemical reaction (like \(NaHCO_3\) and \(HCl\) reaction), atoms rearrange to form products (\(NaCl\), \(H_2O\), \(CO_2\)) with different properties.
• Option D: The reaction is a chemical reaction, not just a phase - change due to superheating of \(NaHCO_3\).

Answer:

C. The atoms in the hydrochloric acid and baking soda rearranged, forming products with different properties