ha! jawab, jawab....(4.2&4.3)

1.	Consider the following reaction that occurs between hydrochloric acid, HCl, and zinc metal: HCl(aq) + Zn(s) → H2 (g) + ZnCl2 (aq) Will this reaction occur fastest using a 6 M solution of HCl or a 0.5 M solution of HCl? Explain.
	Solution: The reaction will occur fastest with 6 M HCl, because it is more concentrated than the 0.5 M solution. In the more concentrated solution there are more moles of HCl present - with a higher concentration of reacting particles, collisions will occur more frequently, leading to a faster rate of reaction.
2.	Again consider the reaction between hydrochloric acid and zinc. How will increasing the temperature affect the rate of the reaction? Explain.
	Solution: Increasing the temperature will most likely increase the rate of the reaction, for two reasons: Particles will move around faster at the higher temperature and thus will collide more frequently, resulting in a faster rate of reaction. Particles will collide with more force. Thus, more particles will likely have sufficient energy (Ea) to reach the activated complex and thus have a successful collision.
3.	Based on the following kinetic energy curves, which reaction will have a faster rate - A or B? Explain. Also, which reaction, A or B, would benefit most in terms of increased rate if the temperature of the system were increased?
	A. B.
	Solution: Reaction B would be faster than Reaction A because it has a lower threshold energy (activation energy). Thus, more particles have at least the minimum amount of energy required for a successful reaction. Reaction A would benefit most by an increase in temperature. Reaction B already have the majority of particles above the threshold energy; having more particles above the threshold would not make a significant difference in the rate.