Question

While preparing whitewash, how many kilograms of sodium chloride dissolved in hot water is needed for every 10 kg of lime?

(a) 1 kg

(b) 1.3 kg

(c) 2 kg

(d) 2.3 kg

I have been asked this question in an interview for internship.

This interesting question is from Distempering in chapter Painting, Varnishing, Distempering, etc of Construction & Building Materials

Answer 1

Correct answer is (b) 1.3 kg

The best explanation: While preparing whitewash, 1.3 kg of sodium chloride dissolved in hot water is needed for every 10 kg of lime. Sodium chloride makes the process of carbonation of calcium hydroxide quick which helps in the making the coating hard.