Question 1 :
The energy&#160;released (exothermic) or adsorbed (endothermic) in a chemical reaction is a result of:<br/>

Question 2 :
A chemical equation is balanced in accordance with the law of

Question 3 :
Which of the following is true with respect to&#160;Law of Conservation of matter?

Question 4 :
When mass is enclosed in a system and none is allowed in or out, it's _____ will never change.

Question 5 :
A balanced chemical equation is in accordance with the law of conservation of masses___________.

Question 7 :
Which one of the following laws directly explains the law of conservation of mass?<br/>

Question 8 :
Which gas law relates the volume of a gas to the number of molecules of the gas?<br/>

Question 9 :
Find the total number of pennies in a tenth of a mole of pennies.

Question 10 :
A sample of ammonia has a mass of $51.1g$. How many molecules are in this sample?

Question 11 :
How many moles are present in $6.023\times 10^{22}$ molecules of $CO_2$?<br>

Question 12 :
What is the volume of $3.0\times {10}^{20}$ molecules of $HCl (g)$?

Question 13 :
The critical volume of a gas is 0.036 $lit. mol^{-1}$. The radius of the molecule will be (in cm):<br/>(Avogadro Number = $6 \times 10^{23}$)<br/>

Question 14 :
Law of definite proportion does not apply to nitrogen oxide because:

Question 15 :
If the ratio of the atoms by mass is altered then :

Question 17 :
In a compound&#160;the ratio of the atoms or element by mass remains always same irrespective of :<br/>

Question 18 :
Different samples of water were found to contain hydrogen and oxygen in the ratio of 1 : 8. This&#160;shows the law of:<br/>

Question 19 :
The ratio of mass of nitrogen and oxygen in nitric oxide is in :

Question 20 :
The % of Copper and Oxygen in samples of CuO&#160;obtained by different methods were found to be&#160;the same.&#160;This proves the law of:<br/>

Question 22 :
Nitrogen reaction with oxygen to form nitrogen (III) oxide.<br/>What will be the volume ratio of the reactants and products of the given reaction?

Question 23 :
14 g of element X combine with 16 g of oxygen. On the basis of this information, which of the following is a correct statement?

Question 25 :
Which set of figures will be obtained after rounding up the following upto three significant figures?<br/>34.216,&#160; 0.04597, 10.4107

Question 26 :
At NTP, 10 litre of hydrogen sulphide gas reacted with 10 litre of sulphur dioxide gas. The volume of gas, after the reaction is complete, would be:

Question 27 :
If $224ml$ of triatomic gas has a mass of $1g$ at $273K$ and $1atm$ pressure, then the mass of one atom is-

Question 29 :
The vapours of organic compound was burnt in oxygen. Equal volume of both gaseous substance were taken at same pressure and temperature. After the reaction, the system was returned to the original condition and it turn out that its volume has not changed. The product of combustion contain 50% $CO_{2}$(g) and 50% $H_{2}O$(g) by volume and no other gas. Find the molecular weight of organic compound (in gram/mol) in question.

Question 30 :
$10$ mL of hydrogen combines with $5$ mL of oxygen to yield water. When $200$ mL of hydrogen at STP is passed over heated $CuO$, the $CuO$ loses $0.144$ g of its weight. State the law illustrated by these chemical combinations.