Coal and Petrol...

The source of heat energy for domestic and industrial purposes are called ___________?

The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its __________ value?

Incomplete combustion of fuels generally give __________ gas.

The increased concentration of carbon dioxide in the air is believed to cause ____________?

Oxides of sulphur and nitrogen dissolve in rain water and form acids. Such rain is called ___________ rain.

Compressed Natural Gas is used for _______________?

Which of the following is generally transported through pipes?

Which of the following is less polluting fuel?

Can coal, petroleum and natural gas be prepared in the laboratory from dead organisms?