Answer to Question #83808 in General Chemistry for wardhere dahir

Question

A fixed mass of marble is reacted with diluted Hydrochloric acid at a constant temperature. explain why the rate of the reaction is increasing if the lumps of marble are reduced in size

Answer 1

Answer on Question #83808, Chemistry/ General Chemistry

A fixed mass of marble is reacted with diluted Hydrochloric acid at a constant temperature. explain why the rate of the reaction is increasing if the lumps of marble are reduced in size

Answer

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

We have a heterogenious reaction where the reactants are in two different phases (CaCO₃(s) and HCl(aq)), and collisions between the reactants can occur only at interfaces between phases. The reaction rate of a heterogenious reaction depends on the surface area of the more condensed phase. When the lumps of marble of fixed mass are reduced in size the surface area increases, the number of collisions between reactants increses and the rate of reaction increases.