PMS MCQs

Bleaching powder releases chlorine-containing disinfecting agents.
It is used in water treatment and bleaching.

Chlorine in controlled amounts disinfects water.
It reduces disease-causing bacteria and viruses.

Calcium and magnesium ions cause hardness.
Hard water forms scale and reduces soap lather.

Hardness ions react with soap molecules.
The insoluble products waste soap and reduce lather.

Temporary hardness is caused mainly by bicarbonates.
Boiling converts them into insoluble precipitates.

Alloys combine metals with other elements.
They are designed for strength, corrosion resistance, or other useful properties.

Brass contains mainly copper and zinc.
It is used in fittings, instruments, and decorative items.

Bronze is primarily copper alloyed with tin.
It is harder than pure copper.

The stomach secretes hydrochloric acid.
It helps activate digestive enzymes and kill many microbes.

Vinegar contains dilute acetic acid.
This acid gives vinegar its sour taste and preservative effect.

Citrus fruits such as lemons and oranges contain citric acid.
It contributes to their sour taste.

Muscle cells can produce lactate during anaerobic metabolism.
This supports short-term energy production when oxygen delivery is limited.