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20 Cards in this Set
- Front
- Back
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What is chemical kenetics
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it is the area of chemistry that is concerned with the speeds or rates of reactions
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What are the 4 factors that allow us to change the rates at which particular reactions occur?
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The physical state of the reactants
The concentrations of the reactants The temperature at which the reaction occurs The presence of a catalyst |
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How do the physical state of the reactants affect the rate of reaction?
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A solid reacting with a gas will need more surface area to react quickly. so liquids and gases that tend to be homogenous can react quickly because there is more surface area to react with
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How do the concentrations of the reactants affect the rate of raction?
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As concentration increases, the frequency with which the reactant molecules collide increases, leading to increased rates
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How does temperature of reactants affect the rate of reaction?
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The rate of reaction increases with temp increase
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How does the presence of a catalyst affect the rate of reaction?
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Catalysts are agents that increase reaction rates without being used up. They speed up the raction by easing the collision rate and thus reducing the reaction time becaus eles energyu is needed. An example is an enzyme
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What is a reaction rate? And what unit is used to measure this?
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the speed of a chem reaction. (M/s) Molarity per second.
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What is molarity?
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it is the Moles of solute per L of solution. moles solute/ L of solution
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How is the average rate of appearance given? for A --> B
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change in concentration of B/ change in time
delta [B]/ delta t |
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How is the average rate of disappearance given? for A --> B
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(-)change in concentration of A/ change in time
(-)delta [A]/ delta t notice the negative signs |
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What is instantaneous rate ?
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it is the rate at a particular moment in the raction.
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What is the initial rate of the reaction?
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it isa when t = 0
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What is the rate law when aA + bB = cC +dD?
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Rate = k[A]^m[B]^n
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What is the rate constant?
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k in the rate law is the rate constant
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What are reaction orders?
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The exponents m and n in the rate law are called reaction orders
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What is the first order?
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When the exponent is 1
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What is 2nd order ?
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when the exponent is 2
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What is zero order?
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When the exponent is 0
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What is the overall reaction order?
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It is the sum of the orders with respect to each reactant in the rate law. if a reaction has 2 first orders the 1 + 1= 2 or second order overall
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What does units of rate equal?
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(units of rate constant)(units of concentration)^2
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