Question Text
Question 3 :
A chemical reaction which involves oxidation of substances and evolution of heat and light is known as:
Question 7 :
How carbon dioxide is stored in the house to extinguish fire?
Question 14 :
When a burning candle is covered with a glass it extinguishes because:
Question 16 :
Statement: Combustion can take place at all temperatures less than an ignition temperature.<br/>State whether the given statement is true or false.
Question 18 :
$KCl{O}_{3}\rightarrow KCl+{O}_{2}$<br/>$I$. The reaction shown above is a combustion reaction.<br/>$II$. Combustion reactions produce oxygen.
Question 19 :
How will you distinguish between fire extinguishing action of water and $CO_2$? 
Question 20 :
Heat of combustion of$CH_{4},C_{2}H_{6},C_{2}H_{4}$ and$ C_{2}H_{2}$ gasses are - 212.8, -373.0, -337.0 and -310.5 Kcal respectively at the same temperature. The best fuel among these gases is :
Question 25 :
The flame of the candle has three zones. The outer zone is blue, the middle zone is yellow and the inner zone is black. Which is correct regarding this?
