# GAMSAT Forum - Gold Standard GAMSAT Prep

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## Chapter 9: Rate Processes in Chemical Reactions

### Re: Chapter 9: Rate Processes in Chemical Reactions

brad.willo2670 wrote:Differential vs Integrated rate laws:

To this point I have had minimal issue with these kinds of questions but something has just confused me regarding the graphing of these laws.

Example 1st order reaction:
Differential equation - rate = k(x)
Integrated equation - ln(X)t = -kt + ln(x)o

My question: is the differential equation ever graphed, or is it always the integrated equation? The integrated equation providing concentration vs time graph.
I have never seen 'rate' on an axis which is what came to confuse me. Does the differential equation simply provide a representation of the relationship of the concentration to the rate as opposed to something that would be directly graphed?

Any mathematical relationship can be graphed. It's just that some graphs are more useful for science than others.

It is definitely within the purview of the GAMSAT that you should be able to be flexible enough to consider what a graph, that you have never seen, should look like (more or less). For example, knowing that y = mx + c is the equation of a straight line, then given rate = k(x), we can confidently say that a graph of rate vs concentration (x) is a straight line with positive slope which intersects the y axis at point 0 (the y intercept).
goldstanda3269

Posts: 1673
Joined: Wed Aug 25, 2010 10:59 pm

### Re: Chapter 9: Rate Processes in Chemical Reactions

This is regarding GEN CHM Chapter 9 Worked solutions for Q7 (CHM-224):

Just to confirm there is a typo in worked solutions as it states answer D is correct not C.

Regards,
Ania
horbowiec.7527

Posts: 71
Joined: Mon Mar 08, 2021 11:35 am

### Re: Chapter 9: Rate Processes in Chemical Reactions

horbowiec.7527 wrote:This is regarding GEN CHM Chapter 9 Worked solutions for Q7 (CHM-224):

Just to confirm there is a typo in worked solutions as it states answer D is correct not C.

It's a trap!

Answer choice C is a correct statement. However, the question states "not" which means that we are looking for the incorrect statement. Answer choice D is indeed correct because it has an incorrect statement.
goldstanda3269

Posts: 1673
Joined: Wed Aug 25, 2010 10:59 pm

### Re: Chapter 9: Rate Processes in Chemical Reactions

Thank you for that, so easy to make a mistake if you're not paying attention!

This is regarding Q24 for GEN CHM Chapter 9: there is no explanation in worked solution for this question, could you add it on please?

Ania
horbowiec.7527

Posts: 71
Joined: Mon Mar 08, 2021 11:35 am

### Re: Chapter 9: Rate Processes in Chemical Reactions

This is regarding GEN CHM Chapter 9 Worked solution for Question 30 (CHM-231):

Could you please kindly offer some additional explanation for this graph and why answer D was chosen. I can't understand it exactly based only on the tables provided in worked solutions.

Regards,
Ania
horbowiec.7527

Posts: 71
Joined: Mon Mar 08, 2021 11:35 am

### Re: Chapter 9: Rate Processes in Chemical Reactions

Please re-check Q24 and Q30 worked solutions in 24 hours.
goldstanda3269

Posts: 1673
Joined: Wed Aug 25, 2010 10:59 pm

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