19. What action would result in an increase in the rate of a chemical reaction?
Answer: C
Using a mortar and pestle to grind a solid reactant to a powder increases the rate of a chemical reaction.
Grinding a solid reactant to a powder increases its surface area, allowing more particles to collide and react simultaneously, thus accelerating the reaction rate.
A) Adding more of the reactants
Adding more of the reactants can indeed increase the rate of a reaction, as it raises the concentration of the reactants. However, this option does not specifically enhance the efficiency of collisions as effectively as increasing the surface area does.
B) Decreasing the temperature of the reactants
Decreasing the temperature of the reactants generally slows down the rate of a chemical reaction. Lower temperatures reduce the kinetic energy of the molecules, leading to fewer successful collisions between reactant particles.
C) Using a mortar and pestle to grind a solid reactant to a powder
Grinding a solid reactant to a powder significantly increases the surface area available for reaction. This increased surface area allows for more effective collisions between reactant particles, thereby enhancing the reaction rate.
D) Sealing the reaction in an airtight container
Sealing the reaction in an airtight container does not inherently increase the rate of a chemical reaction. While it may prevent the escape of gaseous reactants or products, it does not facilitate more effective collisions between reactants.
Conclusion
The action of using a mortar and pestle to grind a solid reactant to a powder is the most effective method for increasing the rate of a chemical reaction, as it maximizes the surface area for interactions. Other options may influence reaction rates but do not achieve the same level of enhancement in collision efficiency as grinding does.