# Calculating rate of a reactionWatch

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#1
How would you calculate the rate of the reaction from a concentration/time graph?

I am going to be carrying out the reaction between iodine and propanone at different temperatures to find the activation enthalpy using the arrhenius equation. However to do this I need k at these temperatures.

k=rate/[a]^m etc. I will have the bottom line [A]^m as I know the concentrations of the reactants I am using and I will have the orders from the colorimetry experiment I just need to find the rate in order to obtain k.

I will be using the quenching method to get the concentration at regular time intervals then, as mentioned before, I will plot a graph of concentration against time.

tl;dr: how do you calculate rate from a concentration/time graph
0
5 years ago
#2
(Original post by Davelittle)
How would you calculate the rate of the reaction from a concentration/time graph?

I am going to be carrying out the reaction between iodine and propanone at different temperatures to find the activation enthalpy using the arrhenius equation. However to do this I need k at these temperatures.

k=rate/[a]^m etc. I will have the bottom line [A]^m as I know the concentrations of the reactants I am using and I will have the orders from the colorimetry experiment I just need to find the rate in order to obtain k.

I will be using the quenching method to get the concentration at regular time intervals then, as mentioned before, I will plot a graph of concentration against time.

tl;dr: how do you calculate rate from a concentration/time graph

Wouldn't the rate at any point be the gradient at that point?
0
5 years ago
#3
(Original post by Davelittle)
How would you calculate the rate of the reaction from a concentration/time graph?

I am going to be carrying out the reaction between iodine and propanone at different temperatures to find the activation enthalpy using the arrhenius equation. However to do this I need k at these temperatures.

k=rate/[a]^m etc. I will have the bottom line [A]^m as I know the concentrations of the reactants I am using and I will have the orders from the colorimetry experiment I just need to find the rate in order to obtain k.

I will be using the quenching method to get the concentration at regular time intervals then, as mentioned before, I will plot a graph of concentration against time.

tl;dr: how do you calculate rate from a concentration/time graph
The gradient of the tangent to the curve ...
0
5 years ago
#4
Take a tangent to the curve and make it as large as possible and then do rise over run. Make sure your units are correct too!
1
#5
(Original post by charco)
The gradient of the tangent to the curve ...

(Original post by ThrashMetal)
Take a tangent to the curve and make it as large as possible and then do rise over run. Make sure your units are correct too!
So would I take the initial tangent at time=0s or what?

Thanks btw both +rep PRSOM at charco
0
5 years ago
#6
(Original post by Davelittle)
So would I take the initial tangent at time=0s or what?

Thanks btw both +rep PRSOM at charco
yes
0
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