[INeedSerotonin]

Hello

This exercise asked me to order the reactions by initial velocity. I would like to confirm with you guys if all that is needed to do is just seeing the concentration.

I think that, the higher the concentration, the higher is the initial velocity, so V(Ea2') > V(Ea3) > V(Ea1') > V(Ea2) > V(Ea1)

Is that correct? Or perhaps I'm missing something here?

[mjc123]

I can't see the reactions. Can you type them out? (Make an effort to help us help you.)

[INeedSerotonin]

I can't see the reactions. Can you type them out? (Make an effort to help us help you.)

Hello!

Unfortunately, I wasn't given any reaction; just this graph above. I noticed a typo: instead of "reacon", it should have been "reaction".

The exercise also says, "The graph below shows the kinetic energy distribution of any population of molecules at a certain temperature", and "Analyzing the graph and considering that these reactions occur in homogeneous systems, with all reagents having an initial concentration of a unit, and are occurring at the temperature in question, it can be concluded that the initial velocities can be arranged as...."

This is all that the exercise gave me.

[mjc123]

I can't see the graph. Can you post it in another format?

[INeedSerotonin]

Here is the direct link to the original (PNG) and to a JPG version

https://i10.servimg.com/u/f10/13/38/65/79/energy10.png

https://i10.servimg.com/u/f10/13/38/65/79/energy10.jpg

[mjc123]

Thanks. My computer is showing me the JPG but not the PNG.

Your order is correct, but I'm not sure you've understood why. Given that it says "all reagents having an initial concentration of a unit", what do you mean by "I think that, the higher the concentration, the higher is the initial velocity"?

[INeedSerotonin]

Thanks. My computer is showing me the JPG but not the PNG.

Your order is correct, but I'm not sure you've understood why. Given that it says "all reagents having an initial concentration of a unit", what do you mean by "I think that, the higher the concentration, the higher is the initial velocity"?

I think that, the highest the "mountain" on the graph, the greatest is the concentration, because there are more molecules with kinetic energy.

Since velocity = k . [reagents]^coefficient, and [reagents] is related to the number of molecules with kinetic energy, the more there are moving molecules, the higher is the velocity.

Am I correct?

[mjc123]

because there are more molecules with kinetic energy.

All the molecules have kinetic energy, just some molecules have more than others. That's what the graph shows.
What is important is the fraction of molecules with kinetic energy greater than Ea, i.e. the fraction that can react. This is given by the area under the curve to the right of Ea (not the height of the Ea line).