Read the following questions carefully and answer them. 

The gas used for artificial fruit ripening of green fruit is —

Oiled paper is?

Of the options listed below, the speed of sound is highest in _____ at 25°C. 

Which of the following is known as artificial silk? 

Which is the most economical method of removing solid matter from water?

Which of the following is used as raw material for the manufacture of rayon?

A proton donor is a ____________ substance.

The brand name Teflon represents which polymer?