The filter in the cigarette reduce the nicotine construct by

Analyze the question The question asks how a cigarette filter reduces the nicotine (and tar) content that reaches the smoker. We need the process by which the filter removes these substances.

Explain the concept

• Adsorption is the process where molecules or particles stick to the surface of a solid. Examples: activated charcoal removing colour or odour, and silica gel removing moisture.
• Absorption is when a substance is taken up into the bulk of another, like a sponge soaking up water.
• Evaporation is a liquid changing to vapour at its surface.
• Burning is combustion, which happens at the lit end of the cigarette and not in the filter.

Show the solution

1. Cigarette filters are made of cellulose acetate fibres, and some contain activated charcoal.
2. As smoke is drawn through the filter, nicotine and tar particles stick to the large surface area of the fibres or charcoal.
3. This surface-sticking process is adsorption, so less nicotine reaches the lungs.
4. Burning and evaporation do not happen in the filter, and absorption (soaking into the bulk) does not describe what the filter fibres do.

Correct answer: B. Adsorption

Tip: Remember "Adsorption = adheres to the surface" (the "d" for "does stick on the outside), while "Absorption = goes inside the bulk". Charcoal and filters are the classic examples of adsorption, and JAMB repeats this often.