Factor of safety is the ratio of the ________ stress to the working stress?

Baffle spacing is generally ________ the I.D. of the shell?

Higher furnace temperature cannot be achieved by use of a lean fuel gas in the furnace by________?

BHC (Benzene hexachloride) is made by the chlorination of benzene________?

Pick out the wrong statement?

Stage efficiency for packed tower varies with the________?