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Limit

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For part 1c), I tried finding the limits (when t tends to infinity) of potassium and sodium separately. But both of the limits turned out to be zero, so how can the quantity of sodium be less than potassium as it says in the question?

This is my part b (ignore the boxed off part, it's wrong.):
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And this is my part c:
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It's not asking about the limit - it's asking you to show that the gradient for Na is always steeper than the gradient for K.
Original post by Joinedup
It's not asking about the limit - it's asking you to show that the gradient for Na is always steeper than the gradient for K.


So I know the gradient for Na is 3 and the gradient for K is 1. How do I show that? The question is worth 4 marks.
(edited 8 years ago)
Is part of my working in part b wrong? taking the ln of both sides , I don't think ln(3e^-aT)=ln(e-^aT) makes the equivalent of ln2-aT=-aT on the following line. Does that mean I have to change the section below it to ln3/aNa - aK too?
Original post by Airess3
Is part of my working in part b wrong? taking the ln of both sides , I don't think ln(3e^-aT)=ln(e-^aT) makes the equivalent of ln2-aT=-aT on the following line. Does that mean I have to change the section below it to ln3/aNa - aK too?


I think yeah, you would have to change it because the line ln(3e-aNaT)=ln(e-akT) would result in ln3-aNaT=-aKT.

Edit: @Airess3: Also, the number of sodium atoms are three times the number of potassium atoms but I think you've written is otherwise.
(edited 8 years ago)
Still stuck on part c. Any answers?
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My answer for c, do I substitute the T from part b) into the current situation?

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