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1.1 Exponential Models

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Question 22

The concentration CCC (in mg/L) of a bioactive compound in a chemical reactor is modelled by the equation

C=pqt C = pq^t C=pqt

where ppp and qqq are constants and ttt is the time in hours since the reaction began.

The relationship between ttt and log⁡10C\log_{10} Clog10​C is linear. The graph of this relationship passes through the vertical intercept (0,1.48)(0, 1.48)(0,1.48) and the point (25,0.73)(25, 0.73)(25,0.73).

a.

Find an equation for this line in the form log⁡10C=mt+c\log_{10} C = mt + clog10​C=mt+c.

[2]
b.

Find the value of ppp and the value of qqq, giving your answers to 3 significant figures.

[2]
c.

According to the model, find the value of ttt when the concentration reaches 10 mg/L.

[2]
Markscheme

1.1 Exponential Models Questions

  1. A Level
  2. /Maths
  3. /1.1 Exponential Models

42 exam-style questions on Edexcel A Level Maths 1.1 Exponential Models. Each one has a worked solution and a mark scheme showing where the marks go.

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