To remove all the moisture from a wet solid it requires exposure to ________ air?

________ rubber is generally used for making ‘O’ rings used for vacuum sealings?

Sand is dried in foundries in a ________drier?

Visco-elastic behaviour exhibited by plastics is a ________ like behaviour?

Presence of 0.3 to 0.5% arsenic in copper increases its________?

Promoter used in NH3 synthesis catalyst is________?