--%>
Assignment Help - homework help

Avogadro's hypothesis Law Principle

Avogadro's hypothesis Law Principle- Berzelius, a chemist tried to correlate Dalton's atomic theory & Gay-Lussac's Law of gaseous volumes. According to his Berzelius hypothesis Equal volumes of all gases under similar conditions of temperature & pressure contain equal number of atoms e.g.

Hydrogen (1 vol) + Chlorine (1 vol)->HCl (2 vol)

Acc to Berzelius hypothesis:

Hydrogen (1/2 atom) + Chlorine (1/2 atom)->HCl (1 compound atom)

But this is indirect conflict of Dalton's atomic theory, so it was rejected.

So a new hypothesis was given by Avogardo.

According to him, An atom is a smallest particle of an element which can take part in a chemical reaction which may or may not be capable of independent existence.

A molecule is the smallest particle of an element or of a compound which have an independent existence. So the smallest particle of a gas is a molecule not an atom, so the volume of gas must be related to the number of molecules rather than atoms.

According to Avogrado's Hypothesis-Equal volume of all gases under similar conditions of temperature & pressure contain equal number of molecules. This is able to explain all the gaseous reactions & now known as Avogrado's Law or Avogrado's principle.

For example-

Hydrogen (1 vol) + Chlorine (1 vol)->HCl (2 vol)

By Avogrado's hypothesis:

n molecule+n molecule gives 2n molecule

1/2molecule of both [Hydrogen + Chlorine] ->HCl (1 molecule)

 Applications of this hypothesis-

(1)In the calculation of atomicity of elementary gases-Atomicity is defined as the number of atoms of the element present in one molecule of the substance e.g. atomicity of N2 is two & O3 is three.

(2)To find the relationship between molecular mass & vapour density of gas-(relative density)

Vapour density of gas=Density of gas/density of hydrogen

           =Mass of [certain vol of gas/same volume of H2] at STP

            =Mass of [n molecule of gas/ n molecule of H2] at STP

            =Mass of [1 molecule of gas/ 1 molecule of H2] at STP

 

                          Vapour density=Molecular Mass/2

(3)To find the relationship between mass & volume of gas-As the

Molecular Mass=Vapour density x 2

Or Molecular Mass=Mass of 22.4 L of gas at STP

Thus 22.4 L of any gas at STP weight is equal to the molecular mass of the gas expressed in grams which is called Gram-Molecular Volume Law (G.M.V.).

   Related Questions in Chemistry

  • Q : Explain the process of adsorption in

    The process of adsorption can occurs in solutions also. This implies that the solid surfaces can also adsorb solutes from solutions. Some clarifying examples are listed below: (i) When an aqueous solution of ethano

    		•
  • Q : Normality of solution containing

    Can someone please help me in getting through this problem. Determine the normality of a solution having 4.9 gm H3PO4 dissolved in 500 ml water: (a) 0.3  (b) 1.0  (c) 3.0   (d) 0.1

    		•
  • Q : Solutions The relative lowering of

    The relative lowering of vapour pressure of 0.2 molal solution in which solvent is benzene

    		•
  • Q : Sugar solution The solution of sugar in

    The solution of sugar in water comprises: (i) Free atoms (ii) Free ions (iii) Free molecules (iv) Free atom and molecules. Choose the right answer from the above.

    		•
  • Q : BASIC CHARACTER OF AMINES IN GAS PHASE,

    IN GAS PHASE, BASICITIES OF THE AMINES IS JUST OPPOSITE TO BASICITY OF AMINES IN AQEUOUS PHASE .. EXPLAIN

    		•
  • Q : Molarity of Nacl solution When 5.85 g

    When 5.85 g of NaCl (having molecular weight 58.5) is dissolved in water and the solution is prepared to 0.5 litres, the molarity of the solution is: (i) 0.2 (ii) 0.4 (iii) 1.0 (iv) 0.1

    		•
  • Q : The Liver Is Responsible For Much Of

    The Liver Is Responsible For Much Of The Pentose Phosphate Activity Explain

    		•
  • Q : Entropy on molecular basis. The

    The equation S = k in W relates entropy to W, a measure of the number of different molecular level arrangements of the system.In the preceding developments it was unnecessary to attempt to reach any "explana

    		•
  • Q : Equimolar solutions Select the right

    Select the right answer of the question. Equimolar solutions in the same solvent have : (a)Same boiling point but different freezing point (b) Same freezing point but different boiling poin (c)Same boiling and same freezing points (d) Different boiling and differe

    		•
  • Q : What do you mean by the term hydra What

    What do you mean by the term hydra? Briefly define it.

    		•