Pine oil and Cresylic acid are used as ________ in the froth floatation process?

Pick out the wrong statement?

Which of the following represents the Virial equation of state?

The sphericity of a solid particle of cubical shape is ________?

Height of coke oven is limited (say maximum upto 7 metres) mainly by the________?

Yield of coke oven gas in low temperature carbonisation of coal is about ________ Nm3 /ton of dry coal?