What is the rate constant k?
The specific rate constant (k) is the proportionality constant relating the rate of the reaction to the concentrations of reactants. The rate law and the specific rate constant for any chemical reaction must be determined experimentally. The value of the rate constant is temperature dependent.
What is the unit for K in rate law?
k is the first-order rate constant, which has units of 1/s. The method of determining the order of a reaction is known as the method of initial rates. The overall order of a reaction is the sum of all the exponents of the concentration terms in the rate equation.
What is the relationship between K and the rate constants?
The ratio of the rate constants for the forward and reverse reactions at equilibrium is the equilibrium constant (K), a unitless quantity. The composition of the equilibrium mixture is therefore determined by the magnitudes of the forward and reverse rate constants at equilibrium.
What are the units of K in the following rate law Rate K X?
For a given reaction with a rate=k[X]2 r a t e = k [ X ] 2 , the rate of reaction is second order. Therefore, the units for k are 1M. s. .
What affects rate constant k?
Increasing the temperature of a reaction generally speeds up the process (increases the rate) because the rate constant increases according to the Arrhenius Equation. As T increases, the value of the exponential part of the equation becomes less negative thus increasing the value of k.
What is the equilibrium constant K?
the equilibrium constant, also known as K eq, is defined by the following expression: where [A] is the molar concentration of species A at equilibrium, and so forth. The coefficients a, b, c, and d in the chemical equation become exponents in the expression for K eq.
Can K value be negative?
A rate constant(k) cannot be negative because it is measuring how fast the concentration changes over time so it cannot be a negative value. … in a single reaction it can’t be negative but in case there are two or more than two chemical reactions rate constant of one reaction may be negative with respect to another one.
What is the rate law expression?
Rate laws or rate equations are mathematical expressions that describe the relationship between the rate of a chemical reaction and the concentration of its reactants. In general, a rate law (or differential rate law, as it is sometimes called) takes this form: rate=k[A]m[B]n[C]p… rate = k [ A ] m [ B ] n [ C ] p …
What happens to K when you reverse the reaction?
The equilibrium expression written for a reaction written in the reverse direction is the reciprocal of the one for the forward reaction. K’ is the constant for the reverse reaction and K is that of the forward reaction. … The equilibrium expression is the reciprocal of that given.
Why equilibrium constant has no unit?
The true equilibrium constant has no units because they are supposed to be calculated using unitless values called activities. But people are lazy and it turns out that for an ideal solution, the molar concentration (without the units) is very close to the activity so we just go ahead and use molar concentrations.
Does rate constant depend on pressure?
The majority of the rate constants were determined at a pressure of approximately 95 Torr. … Given the close agreement between Howard’s low pressure results and our higher pressure values, we conclude that the rate constant does not have a significant pressure dependence for temperatures between 200 and 300 K.
What are the units of K in a zero order reaction?
The rate law for a zero-order reaction is rate = k, where k is the rate constant. In the case of a zero-order reaction, the rate constant k will have units of concentration/time, such as M/s.
What are the units of K in a second order reaction?
where k is a second order rate constant with units of M-1 min-1 or M-1 s-1. Therefore, doubling the concentration of reactant A will quadruple the rate of the reaction.