--%>
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 : Organic and inorganic substances living

    living beings are made up of organic and inorganic substances.according to their complexity of their molecules how can ach of these substances be classified?

    		•
  • Q : Film Mass Transport Sulfur trioxide

    Sulfur trioxide (SO3) is manufactured by the gas-phase oxidation of SO2 over a platinum catalyst: SO2 + ½ O2 à SO3 The catalyst is a non-porous ext

    		•
  • Q : Unit of molality Select the right

    Select the right answer of the question. The unit of molality is: (a) Mole per litre (b) Mole per kilogram (c) Per mole per litre (d) Mole litre

    		•
  • Q : Hybridization Atomic orbitals can be

    Atomic orbitals can be combined, in a process called hybridization, to describe the bonding in polyatomic molecules. Descriptions of the bonding in CH4 can be used to illustrate the valence bond procedure. We must arrive a

    		•
  • Q : Group IV Cations Chromium(III)

    Chromium(III) hydroxide is highly insoluble in distilled water but dissolves readily in either acidic or basic solution. Briefly explain why the compound can dissolve in acidic or in basic but not in neutral solution. Write appropriate equations to support your answer.

    		•
  • Q : What are different mechanisms for

    Nucleophilic substitution reactions in halides containing  - X bond may take place through either of the two different mechanisms,S<

    		•
  • Q : Neutralisation of phosphorous acids

    Provide solution of this question. To neutralise completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H3 PO3) the volume of 0.1 M aqueous KOH solution required is: (a) 40 mL (b) 20 mL (c) 10 mL (d) 60 mL

    		•
  • Q : Chemical formula of detergent Describe

    Describe the chemical formula of detergent?

    		•
  • Q : Problem associated to vapour pressure

    Provide solution of this question. 60 gm of Urea (Mol. wt 60) was dissolved in 9.9 moles, of water. If the vapour pressure of pure water is P0 , the vapour pressure of solution is:(a) 0.10P0 (b) 1.10P0 (c) 0.90P0 (d) 0.99P0

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

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

    		•