Rate Constant Problem: Find n & Rate Constant

Thread starter grint
Start date Jan 26, 2014
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Constant Rate

In summary, the rate constant in a rate constant problem is a proportionality constant denoted by "k" that relates the rate of a reaction to the concentrations of the reactants. It is directly related to the order of a reaction and can be determined from experimental data using various methods such as the integrated rate law and half-life. The rate constant is significant in understanding the kinetics and mechanism of a reaction, and its value can provide information about the stability and energy of the reaction. Temperature also affects the rate constant, with an increase in temperature resulting in a higher rate constant due to increased molecular collisions.

Jan 26, 2014

grint

http://imgur.com/IgOdMW3

Question in the link. How do I go from here and get the rate constant and n values?

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Jan 26, 2014

grint

Equation: k' = k[OH- ]^n

k' and [OH-] measured / calculated

Log both sides of the equation above

log k' = log (k[OH- ]^n )
log k' = log k + n log([OH- ]

which is the same as

log k' = n log([OH- ] + log k
Which you can look at as y = mx + b

m = n, therefore slope = n, n = 1.04
calculate k after that

1. What is the rate constant in a rate constant problem?

The rate constant in a rate constant problem is a proportionality constant that relates the rate of a reaction to the concentrations of the reactants. It is denoted by the symbol "k" and is specific to a particular reaction at a given temperature.

2. How is the rate constant related to the order of a reaction?

The rate constant, k, is directly related to the order of a reaction. The order of a reaction is determined by the sum of the exponents of the concentration terms in the rate law. For example, a first-order reaction will have a rate law of the form rate = k[A], where [A] is the concentration of the reactant. This means that the rate constant, k, is equal to the rate of the reaction when the concentration of the reactant is 1 mol/L.

3. How do you determine the rate constant from experimental data?

The rate constant can be determined from experimental data by using the integrated rate law for a given order of reaction. This involves plotting the natural log of the concentration of the reactant versus time and using the slope of the line to determine the rate constant, k. Alternatively, the rate constant can also be determined by using the half-life of a reaction, which is the amount of time it takes for half of the reactant to be consumed. The half-life can be used to calculate the rate constant using the equation k = ln(2)/t_1/2.

4. What is the significance of the rate constant in a chemical reaction?

The rate constant is an important parameter in understanding the kinetics of a chemical reaction. It helps us to determine the rate of a reaction, how the rate changes with changes in concentration or temperature, and the mechanism of the reaction. The value of the rate constant also provides information about the stability of the reaction and the energy required for the reaction to occur.

5. How does temperature affect the rate constant?

The rate constant is directly proportional to temperature, meaning that as temperature increases, the rate constant also increases. This is due to the fact that an increase in temperature provides more energy for molecules to collide and react, resulting in a faster reaction rate. This relationship is described by the Arrhenius equation, which shows that the rate constant, k, is equal to the pre-exponential factor, A, multiplied by the exponential of the activation energy, E_a, divided by the product of the gas constant, R, and the temperature, T.