Question 2 :
The atomicity of a species is $$x$$ and its atomic weight&#160;is $$y$$. The molecular weight of the species is:<br/>

Question 3 :
Atoms will gain or lose electrons depending on which action takes the :<br/>

Question 4 :
The molecular mass of $$(NH_4)_2CO_3$$ is :Given atomic mass of H = 1, O = 16, C = 12, N = 14.<br/>

Question 8 :
The formula of&#160; stable binary compound which is formed by the combination of lithium&#160;and oxygen is ________.

Question 9 :
The formula of a compound between any group $$2$$ element, $$M$$, and any group $$16$$ element, $$X$$, will be:

Question 10 :
While forming&#160;$$Fe^{2+}$$, the number of electrons lost by $$Fe$$ ion is ________.&#160;

Question 12 :
Number of $$H^{+}$$ ions present in one litre of pure water is_________.

Question 13 :
An atom of one element A has three electrons in its outermost shell, and that of B has six electrons in the outermost orbit. The formula of the compound formed by these two will be :

Question 14 :
How many gram atoms of sulfur are there in 49 g of $$H_2SO_4$$ and of nitrogen in 126 g of $$HNO_3$$?<br/>(Atomic weights of $$H = 1,\ N = 14,\ O = 16,\ S =&#160;32$$)&#160;

Question 16 :
The molecular formula of chloride of a metal $$M$$ is$$MCl_3$$. The formula of its carbonate would be:

Question 17 :
Active mass of 6% solution of compound X is 2.&#160;Molecular weight of X would be :<br/>

Question 18 :
Which of the following best describes the differences between atoms of solid sodium and atoms of liquid sodium?

Question 21 :
What mass of sodium chloride would be decomposed by 9.8 g of sulphuric acid if 12 g of sodium bisulphate and 2.75 g of hydrogen chloride were produced in a reaction?

Question 22 :
A gaseous mixture contains oxygen and nitrogen in the ratio of 1 :4 by mass. Therefore, the ratio of their number of molecules is:

Question 23 :
Which of the following combinations represents a $${2}^{+}$$ ion having a mass number of $$40$$?

Question 24 :
Number of atoms in $$560\ cm^3$$ of oxygen at S.T.P. is :

Question 26 :
Assertion: $$22.4$$ L of ethane at S.T.P contains one mole of hydrogen molecules. Reason: One mole of hydrogen molecules at S.T.P occupies 22.4 L volume.<br/>Choose the correct options.

Question 27 :
Molecular mass of&#160; $${ Na }_{ 2 }{ SO }_{ 4 }$$ . $$10{ H }_{ 2 }O$$ is:

Question 28 :
Which of the following is the best example of lawof conservation of mass?<br>

Question 29 :
In an experiment, $$1.0\, g\, CaCO_3$$ on heating evolved 224 mL of $$CO_2$$ at NTP. What mass of $$CaO$$ (calcium oxide) is formed?

Question 30 :
<br/>The ratio of unpaired electrons present in d orbitals of $$Co^{2+}$$ and $$Cr^{3+}$$<span class="MathJax"><span class="MJX_Assistive_MathML">Co2+ is ____.

Question 31 :
$$\displaystyle n_{1}$$ g of substance X reacts with&#160;$$\displaystyle n_{2}$$ g of substance Y to form&#160;$$\displaystyle m_{1}$$ g of substance R and&#160;$$\displaystyle m_{2}$$ g of substance of S. This reaction can be represented as $$X + Y \rightarrow R + S$$. The relation which can established in the amounts of the reactants and the products will be&#160;: