Question

to measure the amount of calcium carbonate in a seashell, an analytical chemist crushes a sample of the shell to a fine powder and titrates it to the endpoint with of hydrogen chloride solution.the balanced chemical equation for the reaction is:what kind of reaction is this?precipitationacid-baseredoxif you said this was a precipitation reaction, enter the chemical formula of the precipitate.if you said this was an acid-base reaction, enter the chemical formula of the reactant that is acting as the base.if you said this was a redox reaction, enter the chemical symbol of the element that is oxidized.calculate the mass percent of in the sample. be sure your answer has the correct number of significant digits.

Answer 1

The reaction between CaCO3 and HCl is an acid-base reaction, producing CaCl2, CO2, and H2O. Calcium carbonate acts as the base and this reaction demonstrates how carbonates and acids interact to form salts, gaseous CO2, and water.

Step-by-step explanation:

The reaction between hydrochloric acid and calcium carbonate is an acid-base reaction. In this reaction, calcium carbonate (CaCO3) acts as the base. When calcium carbonate reacts with hydrochloric acid (HCl), calcium chloride (CaCl2), carbon dioxide (CO2), and water (H2O) are formed:

CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)

This reaction is relevant in various experiments and analytical chemistry techniques, such as titration to determine the amount of calcium carbonate in a given sample. Additionally, the reaction is illustrative of how carbonates react with acids to form salts, gaseous carbon dioxide, and water. This is also a common phenomenon observed in natural waters with varying calcium carbonate solubilities, influenced by acidity and the presence of carbonic acid from CO2 saturation.