Testing of the knocking characteristics of petrofuels is done in a ________ engine?

Selectivity of the solvent used in solvent extraction should be)________?

A Rotameter through which air at room temperature and atmospheric pressure is flowing gives a certain reading for a flow rate of 100 cc/sec. If helium (molecular weight 4) is used and Rotameter shows the same reading, the flow rate (cc/sec) is________?

Helical screw agitator is used for________?

Which of the following thermocouples is capable of measuring a temperature of -50°C?

A/an ________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor?