What is the name of the process in which coal is heated in absence of air?
The process is called destructive distillation of coal.
Which variety of coal contains maximum amount of carbon?
Anthracite contain maximum amount of carbon.
What is coke?
The greyish-black residue left after destructive distillation of coal is called coke.It is a tough, porous and black substance. It is almost pure form of carbon.