V K Sally and R Goel Solutions for Chapter: Atoms and Molecules, Exercise 2: EXERCISE 3B

An element E forms the following compounds with hydrogen and oxygen.

(a) ${\mathrm{H}}_2\mathrm{E}$ (b) ${\mathrm{EO}}_2$ (c) ${\mathrm{EO}}_3$

Identify the valency of each in the given compounds.

Give two examples of molecules having two different kinds of atoms.

Give two examples of molecules having three different kinds of atoms.

Give two examples of monatomic molecules of an element.

Give two examples of diatomic molecules of an element.

Give one example each of 
(i) a triatomic molecule, 
(ii) a tetra-atomic molecule and, 
(iii) an octa-atomic molecule of an element.

Find the ratio by mass of the combining elements in the following compounds. 
[At mass of: $\mathrm{Ca} = 40, \mathrm{C} =12, \mathrm{O} =16, \mathrm{H} =1, \mathrm{Mg} = 24, \mathrm{Cl} = 35.5, \mathrm{N} =14, \mathrm{S}=32$]
(a) ${\mathrm{CaCO}}_3$   
(b) ${\mathrm{MgCl}}_2$    
(c) ${\mathrm{H}}_2{\mathrm{SO}}_4$   
(d) ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$     
(e) ${\mathrm{NH}}_3$    
(f) $\mathrm{Ca}(\mathrm{OH}{)}_2$
 

Classify each of the following on the basis of their atomicity.
(a) ${\mathrm{F}}_{2 }$
(b) ${\mathrm{NO}}_2$
(c) ${\mathrm{P}}_4{\mathrm{O}}_{10 }$   
(d) ${\mathrm{O}}_3$
(e) $\mathrm{He}$
(f) $\mathrm{Ag}$