Time required for cobalt chloride paper to turn pink when planed just above water surface is called

Which gas turns blue cobalt chloride paper light pink?

A dry cobalt chloride strip,when hydrated,turns:

The ratio of the kinetic energy required to be given to a satellite to escape from the earths gravity to the kinetic energy required to be given to it so that it moves in a circular orbit just above the eart's surface is:

Calculate the work required to raise a body of mass m to a height h just above the earth's surface. Radius of the earth is R and acceleration due to gravity at the earth's surface is g.