Rate constant


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Amy Zheng 2l
Posts: 57
Joined: Fri Sep 29, 2017 7:04 am

Rate constant

Postby Amy Zheng 2l » Sun Mar 11, 2018 11:06 pm

What is the difference between rate constant and reaction rate?
How come increase in concentration doesn't increase rate constant but it does increase rate?

Caroline Cox 1H
Posts: 18
Joined: Fri Sep 29, 2017 7:03 am

Re: Rate constant

Postby Caroline Cox 1H » Sun Mar 11, 2018 11:08 pm

The reaction rate is the actual rate of the reaction occurring while the rate constant is a value you multiply by the current concentration of the reactant in order to get the reaction rate.

Jiun Yue Chung 2I
Posts: 27
Joined: Fri Sep 29, 2017 7:06 am

Re: Rate constant

Postby Jiun Yue Chung 2I » Sun Mar 11, 2018 11:12 pm

The rate constant is deemed a constant for a specific reaction at a specific, constant temperature. This differs from reaction rate because the rate of reaction is the speed in which a reaction is occurring. A good way to think about it is that concentration increasing or decreasing may change the reaction rate while because the rate constant is simiply a scalar of reactant concentrations, it can't change in response.

Lily Sperling 1E
Posts: 49
Joined: Tue Oct 10, 2017 7:14 am

Re: Rate constant

Postby Lily Sperling 1E » Sun Mar 11, 2018 11:12 pm

The reaction rate how fast a chemical reaction occurs when going from R-->P. A reaction rate constant gives the comparative amount of the reaction rates of reactants and products. Meaning that the rate of reaction is influenced the types of reaction, the concentration, pressure, and the temperature when the reactions occurs. The reaction rate constant is influenced only by the temperature or a catalyst-->the reaction rate constant will not change if the only thing changed is the concentration of R

juchung7
Posts: 44
Joined: Fri Sep 29, 2017 7:05 am

Re: Rate constant

Postby juchung7 » Sun Mar 11, 2018 11:14 pm

Also, the rate constant (K) is considered the slope of the graph showing rate of reaction. For first order reactions, the y axis is ln(molar concentration) versus the x axis of time, and the resulting line plotted has a slope of -K, and for second order reactions the y axis is 1/(molar concentration) versus time, and the resulting slop is K.

Vincent Chiang 1L
Posts: 54
Joined: Fri Sep 29, 2017 7:05 am

Re: Rate constant

Postby Vincent Chiang 1L » Sun Mar 11, 2018 11:43 pm

Rate constant is just a constant of proportionality relating how the concentrations of the participants of the reaction relate to the rate of reaction. The rate itself just shows how fast the concentration of one of the participants changes, in units of concentration/pressure per unit time. The rate constant is specific to the reaction and the temperature, so if the rate of reaction increases due to the concentrations of reactants or products increasing (and vice versa), the rate constant will not change.

Ridhi Ravichandran 1E
Posts: 35
Joined: Sat Jul 22, 2017 3:01 am

Re: Rate constant

Postby Ridhi Ravichandran 1E » Mon Mar 12, 2018 1:38 am

A rate constant is simply a proportionality constant included in the rate law. A reaction rate is the actual rate of a reaction, so it tells us how long it takes for reactant to be used up and product to be formed. While a reaction rate always includes units of time, the units of a rate constant vary (units depend on order of reaction).


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