Question

a solid reactant is placed into a beaker of a warm water. the liquid vigorously bubbles as the solid dissolves into the solution. what will most likely happen if the temperature of the liquid is slightly reduced?
more bubbles will be produced because the solution is becoming more concentrated.
fewer bubbles will be produced because of fewer collisions of reactant molecules.
the solid will get smaller at a faster rate because of more collisions of reactant molecules.
the solid will get larger at a slower rate because precipitate is coming out of the solution.

Explanation:

This problem relates to chemical reaction kinetics, a subfield of Chemistry (Natural Science). Reaction rate depends on molecular collisions. Lowering temperature reduces kinetic energy, so reactant molecules collide less frequently. Fewer collisions mean a slower reaction rate, so fewer bubbles (from the reaction) are produced. The first option is wrong (concentration doesn't increase with temp drop). The third is wrong (lower temp slows, not speeds, collisions). The fourth is wrong as the process is dissolution, not precipitation forming to make the solid larger.

Answer:

B. Fewer bubbles will be produced because of fewer collisions of reactant molecules.