Question

What is the solid residue that remains after heating of coal in the absence of air?

(a) Resin

(b) Coke

(c) Powder

(d) Whisker

This question was posed to me during an online interview.

My doubt stems from Cements, Metallurgical Coke and Synthetic Resins in division Miscellaneous Materials of Engineering Material & Metallurgy

Answer 1

Right answer is (b) Coke

The best I can explain: Coke is an important element used in iron-making and metallurgical applications. It is the solid and cellular residue that remains after bituminous coal is heated in the absence of air. This is done at a temperature above which thermal decomposition occurs.