Important Questions on Combustion and Flame
Why is water not suitable for extinguishing a fire in an electrical appliance? 
Name and give chemical equations to show the products of the combustion reaction in
(a) limited supply of air.
(b) sufficient supply of air. List the different methods by which a fire can be extinguished. What kind of fires can effectively be put out by water? What kind of fires is it not suitable for? Give reasons for both cases. How does carbon dioxide extinguish a fire? What is calorific value of a fuel? Why is hydrogen not used as a fuel though it has the highest calorific value? How are fuels classified on the basis of their physical state? Give two examples of each. How is burning of fossil fuels thought to be related to global warming? 
