Question

in your lab group you combined vinegar and baking soda and observed the results shown in the picture. choose all of the evidence that supports that a chemical change has occurred a a gas is produced b the color changed c bubbling occurred d the baking soda dissolved e there is a change in the composition of the reactants

Explanation:

• Option A: When vinegar (acetic acid) reacts with baking soda (sodium bicarbonate), a chemical reaction occurs: $\ce{CH_3COOH + NaHCO_3 -> CH_3COONa + H_2O + CO_2↑}$, and $\ce{CO_2}$ gas is produced. Production of a gas is evidence of a chemical change.
• Option B: Vinegar and baking soda are typically colorless (or the baking soda is white powder, vinegar is clear), and their reaction does not involve a color change, so this is not evidence.
• Option C: The bubbling is due to the production of $\ce{CO_2}$ gas (from the reaction), so bubbling (gas evolution) is evidence of a chemical change.
• Option D: Dissolving baking soda in vinegar is a physical process (solvation) before the chemical reaction, but the reaction itself is chemical. However, dissolving alone is not evidence of a chemical change (it can be physical). The key is the reaction producing gas, not just dissolving.
• Option E: In a chemical reaction, the reactants (vinegar and baking soda) are converted into new substances (sodium acetate, water, carbon dioxide), so there is a change in the composition of the reactants (they are transformed), which is the definition of a chemical change.

Answer:

A. A gas is produced, C. Bubbling occurred, E. There is a change in the composition of the reactants