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Thanks for your advice. I have put up a case on IB Answers

Thank you!

That is a fair point, SusanAs temperature increases, the rate increases; the largest contributor to this change, by some margin, is the shift of the Maxwell-Boltzmann curve, which increases the probability of successful collisions...

Hi Austin, As Paul has already said your comments are very valid. I've altered the question so that it only refers to very weak acids and given some more detail in the answer. Thank you for your input.

Thanks for the suggestion. I've considered comparing two approaches for other experiments but hadn't for kinetics.

You raise a very good point, Austin. This question relies on an oversimplification of the model ('Weak acids have strong conjugate bases" is not correct; I like your correction). We've simplified the model to help with understanding, but in this case,...

Hi I am very surprised to see the following answers in the May 2026 P2 TZ1 answer that in 3(c)(ii), the IB does not accept probability of collision on effect of increase temp on rate. However in the IB guide, it is clearly written...

Most of my students chose option D for question 6, and I think it is probably the most appropriate answer following the IB guidance of choosing the "best" option.  However, I'm wondering if there is potential for confusion amongst more careful...

Thanks for this contribution John. It is a subtle point that 2A is not the same as A2 but it is important in terms of arriving at the overall equation. Thank you for noticing it and for pointing it out. It is changed now.

Hi Demet, No you are not missing anything! My mistake as magnesium sulfate is very soluble in water. I've corrected it now.