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

C = pq^t

where $p$ and $q$ are constants and $t$ is the time in hours since the reaction began.

The relationship between $t$ and $log_{10} C$ is linear. The graph of this relationship passes through the vertical intercept $(0, 1.48)$ and the point $(25, 0.73)$ .

Find an equation for this line in the form $log_{10} C = mt + c$ .

Find the value of $p$ and the value of $q$ , giving your answers to 3 significant figures.

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

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

C = pq^t

where $p$ and $q$ are constants and $t$ is the time in hours since the reaction began.

The relationship between $t$ and $log_{10} C$ is linear. The graph of this relationship passes through the vertical intercept $(0, 1.48)$ and the point $(25, 0.73)$ .

Find an equation for this line in the form $log_{10} C = mt + c$ .

Find the value of $p$ and the value of $q$ , giving your answers to 3 significant figures.

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

1.6 Exponentials and logarithms

Question 62

Markscheme

1.6 Exponentials and logarithms

Question 62

Markscheme

1.6 Exponentials and logarithms

Question 62

1.6 Exponentials and logarithms Questions

1.6 Exponentials and logarithms

Question 62

1.6 Exponentials and logarithms Questions