[JNW2]

Why the acid strength [tex] HClO4 > HCl > H2SO4>HNO3 [/tex]

Is These includes the factors
1) polarizability of conjugate base
2) electronegativity of central atom
3) s,p and s,p,d hybridization ?

Could you help me to explain this ?

[orthoformate]

The rules on this forum are that you have to show us your best guess before we can help you. In order to make an educated guess I would google those factors you need to include.

[JNW2]

The rules on this forum are that you have to show us your best guess before we can help you. In order to make an educated guess I would google those factors you need to include.

ClO4- more stable than Cl-  because of  the more atoms or the volume for electron polarizability ?

 Cl- more stable than HSO42- because of the effect of leaving group
the electronegativity of Cl > S  and the dissociation HSO4- to SO42- ?

HSO42- more stable than NO3- because of the more orbitals  s,p,d
in S than N which has only s,p orbitals?

[JNW2]

Any help is much appreciated.

[AWK]

Your problem is quite nice explained in Wikipedia (acid strength). Also all factors that influence acid strength are discussed.
But one sentence in wikipedia is not true: " and sulfuric acid (H2SO4). In aqueous solution, each of these essentially ionizes 100%". Sulfuric acid is strong, but only loosing the first proton, and may be treated as completely ionized (for student calculations within 5% error) only for concentration ~10^-4 or less (since K₂). And a few, relatively common, strong acids are missing, namely H₄P₂O₇, HMnO₄, H₂CrO₄, H₂Cr₂O₇.
In this article also super acids (with wikipedia link) are mensioned. HClO₄ is treated as superacid.

[docnet]

Chlorine is a more electronegative central atom than Sulfur, and Sulfer is more electronegative than Nitrogen.

HClO4 is a stronger than acid than HCl because the dipole moments caused by the O draw the electron density away from the hydrogen molecule. 

As for why H2SO4 is a stronger acid than HNO3, here's a link to the Boisestate chemistry website. Basically the formal charges on the S is more positive than the one on the N, and counter intuitively this makes the Hydrogen atoms in H2SO4 have a more positive character.

EDIT: forgot to include the link

https://chemistry.boisestate.edu/richardbanks/inorganic/acid-base/acid_base9.htm