General Science Questions

In purifying drinking water alum is used for coagulation of mud particles.

The best colours for sun umbrella is black on inside and white on top of the umbrella. As black colour absorbs sun rays it should not be up side.

The first step in the refining of petroleum is distillation i.e,  the fractionation of crude oil in atmospheric and vacuum distillation towers.

The first process petroleum refinery is known as distillation. In this process, crude oil is heated and fed into a distillation column. As the temperature of the crude oil in the distillation column rises, the crude oil separates itself into different components, called "fractions." The fractions are then captured separately. Each fraction corresponds to a different type of petroleum product, depending on the temperature at which that fraction boils off the crude oil mixture.

The cross section of a chisel is usually octagonal.