Chapter 16, Problem 55A

Apply collision theory to explain why powdered zinc reacts to form hydrogen gas faster than large pieces of zinc when both are placed in hydrochloric acid solution.

Interpretation Introduction

Interpretation:

This is to be explained through collision theory that powdered zinc reacts to hydrogen gas faster than a larger piece of zinc when both are placed in hydrochloric acid solution.

Concept introduction:

According to collision theory, for a reaction to occur, the molecule must collide at both the correct orientation and with enough energy. It states that for the existence of a chemical reaction.

Answer to Problem 55A

The surface area of the powdered zinc is greater than the larger piece of the zinc. Therefore, powdered zinc has much free space to collide HCl on it than a solid chunk. Therefore, it produces hydrogen gas faster.

Explanation of Solution

Powdered zinc has a greater surface area. According to collision theory, molecules collide at both the correct orientation and with enough energy to result in a reaction. The greater surface area of the powdered zinc causes it to react faster because more reactant molecules or atoms are free to collide with hydrochloric acid around it.

Conclusion

The rate of a chemical reaction is affected by several things like the concentration of the substances, temperature, surface area and presence of catalyst or inhibitors.