Allotropy & Allotropes Of The Oxygen

Allotropy & Allotropes Of The Oxygen

Allotropy & Allotropes Of The Oxygen

The word Allotropy has been derived from two words Allos means other and Tropes means form. Thus it is defined as “The existences of more than one forms of an element in same physical state having same chemical properties but different physical properties are called allotropes or allotropic forms and this phenomenon or process is called allotropy”.

Example: Diamond and graphite are the allotropic form of carbon.

Oxygen (O₂) is color less.

•  O₂ is for life. Plants and animals cannot live without it.
• The most energetic ultra violet (UV) radiations, which are harmful for both plants and animals, are absorbed by oxygen in atmosphere.
• Rockets carry liquid O₂ as a fuel in space.
• Oxygen cylinders are used to aid patients of pneumonia and gas poisoning.
• Oxygen cylinders are used for breathing, while climbing on mountain, flying at high altitudes and in submarines.

Ozone (O₃): is blue.

• The less energetic ultra violet (UV) radiations, which are very harmful for both plants and animals, are absorbed by ozone.
• Ozone is poisonous, therefore can be used for disinfecting water.
• Ozone is used to sterilize air in crowded areas such as underground railway stations and slaughter houses.

Read More

Physical Properties Comparison

The Comparison of Physical Properties of Matter between Solids, Liquids and Gases

The Comparison of Physical Properties of Matter between Solids, Liquids and Gases:

Properties	Solid	Liquid	Gas
Shape	Solids have definite shapes	Liquids don’t have definite shapes. They take the shape of container.	Gases also  don’t have definite shapes. They also take the shape of container.
Volume	Solids have fixed volume	Liquids also have fixed volume	Gases take on the  volume of their container.
Compressibility	Solids are not compressible.	Liquids are difficult to compress	Gases are easily compressible.
Density=	Solids normally have high density	Liquids have medium density	Gases have very low density
Kinetic energy	It has low kinetic energy	It has medium kinetic energy	It has highest kinetic energy
Movement of particles	The particles in solids have restricted movement, i-e vibrational motion.	Liquids have less restricted movement in their particles or molecules.	The particles or molecules of gases move freely.
Kinetic Energy of molecules	Solids have lowest K.E.	Liquids have medium K.E.	Gases have highest K.E.
Molecular arrangement	Molecules in solids are highly arranged.	Molecules in liquids have somewhat regular arrangement	Molecular arrangement in gases is very irregular
Rate of diffusion	No diffusion	Rate of diffusion is lower than gases	Rate of diffusion is highest

Read More

Calculation Of Weight & Mole % Of Sulphur In 50g Of Sulphuric Acid

Calculation Of Weight & Mole % Of  Sulphur In 50g Of Sulphuric Acid

Calculation Of Weight & Mole % Of  Sulphur In 50g Of Sulphuric Acid

Data Given:               

       Mass or amount or quantity of H₂SO₄      =         50g

Requirement:       

      Percentage of Mass or weight of sulphur in 50g H₂SO₄    =  ?

      Percentage of Moles of sulphur in 50g H₂SO₄                   = ?

       Solution For Calculation:    

      

     As we know that

     

 Number of Moles of H₂SO₄        =               Mass / Molar Or Molecular Mass 

    

 Relative molecular mass (Mr) of H₂SO₄    =     H₂            +            S              +         O₄   

 Relative molecular mass (Mr) of H₂SO₄   =   (2×1)        +         (1 × 32)           +     (4×16)

 Relative molecular mass (Mr) of H₂SO₄    =      2              +             32                    +        64

 Relative molecular mass (Mr) of H₂SO₄    =     98a.m.u

Now Putting the values in above equation 

Number of Moles of H₂SO₄            =    50 / 98        

Number of Moles of H₂SO₄            =    0.51      Answer.

Number Moles of S in 50 g H₂SO₄

H₂SO₄             :                   S

1                        :                      1

0.51: 1               ::                    1 : x

0.51x                 =                   1 × 1

X                       =                      

X                       =                      1.96

Moles of sulphur is 1.96 moles in 50g of sulphuric acid (H₂SO₄).

Number Moles of S    in 50 g H₂SO₄   =   (1.96 / 0.51) × 100

 Number Moles of S    in 50 g H₂SO₄   =       3.843 × 100

  Number Moles of S    in 50 g H₂SO₄  =      384.313%

Percentage of Mass or weight of sulphur in 50g H₂SO₄   =  (32 / 50) × 100   

Percentage of Mass or weight of sulphur in 50g H₂SO₄    =  0.64    10    

Percentage of Mass or weight of sulphur in 50g H₂SO₄    =  64%

Read More

Electronegativity Importance & Uses For Chemists

Electronegativity Importance & Uses For Chemists

Electronegativity Importance & Uses For Chemists

Electro-negativity is important for chemists because it has following usages:

• Electro-negativity is used to predict the reactivity and bond type. The elements having highest value of electro-negativity are more reactive. Such as Fluorine (F) with highest electro-negativity value of 4.0 is the most reactive element of the periodic table.
• Electro-negativity is used to calculate the bond type as follows
• If electro-negativity difference is 1.7 then the bond is 50% covalent and 50% ionic.
• If the electro-negativity difference is greater than 1.7 then the bond is ionic.
• If the electro-negativity difference is less than 1.7 then the bond is covalent.
• If the electro-negativity difference is less than 0.5 then the bond in an atom is non-polar.
• If the electro-negativity difference is greater than 0.5 but less than 1.7 then the bond is polar covalent one.

]]]]]]]]]]]]]]]

The Inertness of Nobel gases.

The Elements form bonds to complete their outermost shell. Nobel gases have complete outermost shells therefore they don’t make bonds with other elements, because they don’t need to complete their outermost shells.

]]]]]]]]]]]]]]]

 Why it is necessary to classify the Elements? Explain with reasoning.

 Ans: Up till now approximately 118 elements have been discovered. Thus it is difficult to study each and every element separately. Therefore it is necessary to classify these elements, in order to study their physical and chemical properties.

]]]]]]]]]]]]]]]

Discuss the importance of groups and periods in the modern periodic table?

Groups show the number of electrons in the last shell of an element, while periods show the total number of shells present in one atom of a element. These both: shells and electrons are extremely important in studying the properties an element.

]]]]]]]]]]]]]]]

Read More

The Evolution Of Periodic Table

The Evolution Of Periodic Table

The Evolution Of Periodic Table

Various attempts were made by scientists to give more précised periodic table: E. g:

• Dobereiner proposed triads in 1820,
• Newlands proposed Octaves in 1860
• Mendeleev for the first time classified elements on the basis of their atomic masses in 1865.

All these attempts mentioned above had draw backs. After the discovery of proton, proton number built up. On the basis of which in 1913 Moseley presented an accurate periodic table of elements. He arranged elements according to their atomic number. As result similar elements were placed in same group and different elements were placed in different groups. Now it is easy to understand and determine both chemical and physical properties of elements.

The Modern periodic law? Explain with examples.

Ans. This law states that “the physical and chemical properties of an element are the periodic functions of their atomic number”. E. g:

• The physical and chemical properties of Alkali metals repeat after an interval. As result the Alkali metals having similar properties are placed in the same group. 
• The physical and chemical properties of halogens also repeat after an interval. As result all the halogens (salt formers) are placed in the same group. And so on.

Read More

Avogadro’s Number & Mole Relationship

Avogadro’s Number & Mole Relationship

Avogadro’s Number & Mole Relationship

We know that the number of particles in one mole of a substance is called Avogadro’s number and the amount of substance in grams containing Avogadro’s number of particles (6.02 ) is called Mole.

Relation between Avogadro’s number and mole of any substance.

Substace	No. of particles	No. of Moles	Amount (weight)
H	6.02x 1023    atoms	1	1g (Gram Atomic Weight)
H2	6.02x 1023   molecules	1	2g (Gram Molecular weight)
H2O	6.02x 1023    molecules	1	18(Gram Molecular weight)
Na+1	6.02x 1023     ions	1	23 (Gram Ionic Weight)
NaCl	6.02x 1023  Formula units	1	58.5(Gram Formuls Weight)

Comment that concepts are vital for chemists.

 As Chemistry is a very important branch of science, and for complete understanding of any branch of science it is extremely important or vital to understand the basic concepts of particular topics about that branch of science.  

Read More

The Most important Cat-ions & An-ions

The Most important Cat-ions & An-ions

The Most important Cat-ions & An-ions

As we all know that the ions are the Charged Particles and there are two main and very important types of the Ions. One of type of the ions are Cat-ions and the seconf type of the ion is An-ions. When any atom loses an electron then the An-ion is formed and the atom who gains/accepts this electron becomes Cat-ion. Thus the Cat-ions are formed by the accepting-gaining the electrons and the An-ions are formed by the losing-donating the electrons. And Now we have Brought a very and most important Cat-ions and the An-ions for you people online free at Onllogy.com.

These Important ions are as under at #Onllogy

Common Cat-ions
Common Name	Formula	Common Name	Formula
Aluminum	Al3+	Iron(III)	Fe3+
Calcium	Ca2+	Lead(II)	Pb2+
Chromium(II)	Cr2+	Lead(IV)	Pb4+
Chromium(III)	Cr3+	Magnesium	Mg2+
Copper(I)	Cu+	Potassium	K+
Copper(II)	Cu2+	Silver	Ag+
Hydrogen	H+	Sodium	Na+
Iron(II)	Fe2+

Formation of the Cat-Ions

 Atoms                                                      Cat-ions

    H                         ••••►                           H⁺¹     +      1e⁻

    Na                       ••••►                           Na⁺¹   +      1e⁻

     Ca                        ••••►                           Ca⁺²    +      2e⁻ 

Common Cat-ions
Common Name	Formula	Common Name	Formula
Aluminum	Al3+	Iron(III)	Fe3+
Calcium	Ca2+	Lead(II)	Pb2+
Chromium(II)	Cr2+	Lead(IV)	Pb4+
Chromium(III)	Cr3+	Magnesium	Mg2+
Copper(I)	Cu+	Potassium	K+
Copper(II)	Cu2+	Silver	Ag+
Hydrogen	H+	Sodium	Na+
Iron(II)	Fe2+

Formation of the An-ions

Atoms                                                       An-ions

 Cl  +   1 e⁻                     ••••►                           Cl⁻¹

 O  +    2e⁻                      ••••►                           O⁻²

Read More