Question

The data below shows the concentration of nicotine smoked by a smoker taking 10 puffs/minute.

Graph: "Smoking Cigarette" - concentration of nicotine in blood (mg/cm³) plotted against time (minutes).

(i) With reference to the above graph, explain the concentration of nicotine in the blood at 10 minutes.

Hint:

Read the height of the line at 10 minutes and explain that continuous puffing keeps adding nicotine faster than the body removes it.

Answer 1

Step 1: Read the graph correctly:
The x-axis shows time in minutes from 1 to 15. The y-axis shows nicotine in blood in \(\mathrm{mg/cm^3}\).
The line starts near 0 at 1 minute and rises in a straight slope. It keeps rising until the 10 minute mark.

Step 2: Find the value at 10 minutes:
At 10 minutes the line touches its highest point, which is about 45 \(\mathrm{mg/cm^3}\).
This is the peak of the whole graph. No other time has a higher nicotine level.

Step 3: Explain why the level is highest here:
The smoker takes 10 puffs every minute. Nicotine in the smoke passes through the thin lining of the lungs into the blood very fast.
Until the 10th minute, nicotine enters the blood faster than the liver can break it down and the kidneys can remove it.
So the blood level keeps adding up and reaches the maximum at 10 minutes.

Step 4: Link to the fall after 10 minutes:
After the 10th minute the line drops steeply to about 20 \(\mathrm{mg/cm^3}\) at 11 minutes. This shows that smoking has stopped and the body is now clearing nicotine.
The slow fall that follows shows steady breakdown and removal.

Final Answer:
At 10 minutes the nicotine concentration in the blood is at its maximum, about 45 \(\mathrm{mg/cm^3}\), because absorption from smoking is faster than removal.