consider the reaction below.\nc₂h₄(g) + h₂(g) → c₂h₆(g)\nwhich change would likely cause the greatest…

consider the reaction below.\nc₂h₄(g) + h₂(g) → c₂h₆(g)\nwhich change would likely cause the greatest increase in the rate of the reaction?\n○ decrease temperature and decrease pressure\n○ increase temperature and decrease pressure\n○ decrease temperature and increase pressure\n○ increase temperature and increase pressure
Answer
Explanation:
Step1: Understand reaction - rate factors
Reaction rate increases with higher temperature and higher concentration. Pressure increase for gas - phase reactions is equivalent to concentration increase.
Step2: Analyze temperature effect
Increasing temperature provides more kinetic energy to reactant molecules, increasing the frequency of effective collisions and thus the reaction rate. Decreasing temperature has the opposite effect.
Step3: Analyze pressure effect
For the given gas - phase reaction $C_2H_4(g)+H_2(g)\rightarrow C_2H_6(g)$, increasing pressure will increase the concentration of reactant gases. According to the collision theory, a higher concentration leads to more frequent collisions between reactant molecules, increasing the reaction rate. Decreasing pressure will decrease the reaction rate.
Answer:
increase temperature and increase pressure