Hey guys! I'm stuck on some study guide problems... (On the bottom of this, I put what answers make sense to me)
A) A factor that affects the speed of heterogeneous reactions but not of homogeneous reactions is
1)nature of reactants 2)concentration of reactants 3)area of contact between different phases 4) molecular size 5)the orientations of the molecules during a collision 6)None of the above
B)The sequence of chemical reactions that gives rise to a new overall chemical change is the
1)collision pathway 2)reaction mechanism 3)elementary process 4)reaction system 5)none of the above
C)The rate of a chemical reaction in the forward direction doesn't depend on
1)number of collisions per second between reactant molecules 2)orientation of molecules during collision 3)the temperature 4)the potential energy of the products 5)the activation energy
D)The rate of reaction increases primarily with temperature because:
1)as activation energy is lowered, temperature increases 2)changing the temperature alters the mechanism 3)The heat of reaction is increase 4)An endothermic process is helped along by increasing the temperature 5)A greater fraction of the molecules possess the activation energy
Maybe the answers:
A)I know this has to do with surface area, so maybe the answer is 4 molecular size (?)
B)Maybe 2 reaction mechanism
C)Maybe 4 because the potential energy of products deals with the reverse reaction?
D)Maybe 5? because when you graph
Thanks guys!
I agree with your answers to B, C, D. I'm inclined to choose 3 for A since that has more to do with surface area than 4.
A) To identify the factor that affects the speed of heterogeneous reactions but not homogeneous reactions, let's break down the options:
1) Nature of reactants: This can affect the speed of both heterogeneous and homogeneous reactions.
2) Concentration of reactants: This can affect the speed of both heterogeneous and homogeneous reactions.
3) Area of contact between different phases: This is specific to heterogeneous reactions where different phases are involved, so it fits the criteria.
4) Molecular size: This can affect the speed of both heterogeneous and homogeneous reactions.
5) The orientations of the molecules during a collision: This can affect the speed of both heterogeneous and homogeneous reactions.
6) None of the above: This isn't a viable option if we are looking for a factor that affects the speed of heterogeneous reactions.
Based on the analysis, the correct answer is 3) area of contact between different phases, as it has a specific impact on the speed of heterogeneous reactions.
B) To identify the sequence of chemical reactions that gives rise to a new overall chemical change, let's examine the options:
1) Collision pathway: This refers to the path followed by the reactants during a collision, but it doesn't encompass the entire sequence of reactions.
2) Reaction mechanism: This describes the step-by-step sequence of individual reactions that occur to produce the overall change, making it the correct answer.
3) Elementary process: This refers to individual steps within a reaction mechanism, not the entire sequence.
4) Reaction system: This is a broad term that encompasses all components involved in a reaction, but it doesn't specifically refer to the sequence of chemical reactions.
5) None of the above: This isn't a viable option as we are specifically looking for the correct term.
Based on the analysis, the correct answer is 2) reaction mechanism.
C) To identify the factor that does not affect the rate of a chemical reaction in the forward direction, let's examine the options:
1) Number of collisions per second between reactant molecules: This is important for the rate of any reaction.
2) Orientation of molecules during collision: This can affect the rate of some reactions, so it is not the correct answer.
3) Temperature: Changes in temperature can affect the rate of a reaction, so it is not the correct answer.
4) Potential energy of the products: This can affect the reverse reaction, but it doesn't specifically relate to the rate of the forward reaction.
5) Activation energy: This is an important factor in determining the rate of reaction, so it is not the correct answer.
Based on the analysis, the correct answer is 4) the potential energy of the products.
D) To identify why the rate of reaction primarily increases with temperature, let's examine the options:
1) As activation energy is lowered, temperature increases: This implies a cause and effect relationship that is not always true, so it is not the correct answer.
2) Changing the temperature alters the mechanism: While temperature can affect the rate, it doesn't necessarily alter the reaction mechanism itself, so this is not the correct answer.
3) The heat of reaction is increased: Heat of reaction relates to the enthalpy change, but it is not the primary reason why the rate increases with temperature.
4) An endothermic process is helped along by increasing the temperature: This statement is partially true, but it doesn't capture the primary reason for the rate increase.
5) A greater fraction of the molecules possess the activation energy: Increasing temperature provides more energy to molecules, increasing the fraction that surpasses the activation energy barrier, making this the correct answer.
Based on the analysis, the correct answer is 5) A greater fraction of the molecules possess the activation energy.