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### Tangent line

Posted: Sun Feb 25, 2018 10:56 pm
When we're trying to determine the rate of a reaction and want to draw a line tangent to the curve would it matter where we take the tangent line from (at the beginning, end or middle of the curve)?

### Re: Tangent line

Posted: Sun Feb 25, 2018 10:57 pm
Yes, as taking the tangent at the beginning would mean the reaction is misrepresented as going faster than it is at the end, and the reverse would be true for taking the tangent at the end.

### Re: Tangent line

Posted: Sun Feb 25, 2018 10:59 pm
It does matter where we draw the tangent line because in most reactions, the rate decreases as the reaction proceeds. This means that the initial rate is higher than the rate near the end of the reaction which also means that the slope of the tangent line will be greater as well near the beginning of the reaction than the end of the reaction.

### Re: Tangent line

Posted: Sun Feb 25, 2018 11:07 pm
What is the ideal place to take the tangent line from then? How do you decide where to take the tangent line from?

### Re: Tangent line

Posted: Sun Feb 25, 2018 11:45 pm
Yes the reaction rate will change as the reaction proceeds. We will always take the instantaneous rate closest to t=0 since this is the maximum rate.