the strenght of acid and base

The order of acid strength solution of HCl, HClO, HClO2, HClO3, and HClO4



How you can indulge in acid strength of the compounds of HCl, HClO, HClO2, HClO3, and HClO4? What parameters you can use to measure the degree of acidity of these compounds?

Trend strength above acid can be determined with the following parameters:
Acid strength will be greater with increasing number of oxygen atoms attached to the center.
Acid strength will be even greater with the increasing size of the central atom oxidation number (in kasusini the Cl atom)

By using the above parameters of course you can sort the acid strength of the above compounds is not it? To know "Kenapanya" then you can read the following description and Structure acids are:



Qualitative explanation

According to the Bronsted-Lowry acid is a proton donor, so the acid strength is determined by how easily a species to donate protons. The easier a proton donating species, then the acid will become stronger as well as vice versa. Easy or not an acid species to donate protons can be seen from how much the price of Ka and how much acid is ionized in solution.

We note compounds HClO, HClO2, HClO3, and HClO4 are ionized in water by reaction as follows:

HClO + H2O -> H3O + + clo-
HClO2 + H2O -> H3O + + ClO2-
HClO3 + H2O -> H3O + + ClO3-
HClO4 + H2O -> H3O + + ClO4-

The greater the number of ionized species, the amino acid will be stronger and vice versa. How can we determine the above acids, which one would ionized perfect and which are ionized in part to our use in determining the strength of acid?

How you can use is to determine the stability of residual acid anions in the solution of anion clo-, ClO2-, ClO3-, and ClO4-. The more stable anionnya the more acidic ionized and automatically stronger acidic.

How you can determine the stability of these anions? The answer is by seeing how these anions distribute the negative charge (or in other words look at the structure resonance). The greater the amount of oxygen atoms above the more stable the anion, because the more the number of oxygen atoms that can accept the negative charge distribution, this also means that the anion has a lot of resonance structures.

As an illustration, we carry a lighter load with 4 people instead of carrying the same load with two people. For the above case let's just bebanya is a negative charge, ClO4-ions can distribute the negative charge on the 4 oxygen atoms while the ion-ClO3 can only distribute the negative charge on the 3 oxygen atoms, two to ClO2-ion, and unfortunately ion-CLO can not distribute content negative, so that ClO4-anions is much more stable than the other.

Thus the above sequence is a stable anion-ClO4> ClO3-> ClO2-> clo-. Remember the more stable anion which means more acid is ionized so that the greater acid strength by sebabitu acid sequence of the greatest strengths is HClO4> HClO3> HClO2> HClO.

By looking at the price of Ka / pKa

Price pKa of the acid above is:

HCl pKa = -8
HClO pKa = 7.53
HClO2 pKa = 2
pKa HClO3 = -1
pKa HClO4 = -10

The lower the price pKa the stronger acid, so according to the price above the acid strength of the largest are HClO4> HCl> HClO3> HClO2> HClO. From the data above the price pKa HCl, HClO3, and HClO4 is negative because these acids are strong acids. HCl strength is almost the same can be said with HClO4, this possibility is because HCl in the form of solution [HCl (aq)] as an ionic compound is so easy to let go of its protons HCl. (Gaseous HCl is a weak acid because the H-Cl bond in the form of gas is covalent).

Note:
HCl in the first discussion I was not included because we can not compare the strength of hydrochloric acid in kualittaif with HClO, HClO2, HClO3, and HClO4 is an oxy acid. We are more easily compare the strength of acidity of HCl is qualitatively with HI, HBr, or HF.


posted by : Name : vebria Ardina
NIM : RSA1C110020
class : ISSTE of Chemistry

0 komentar:

Poskan Komentar

Write here, about you and your blog.
 
Copyright 2009 Chemistry All rights reserved.
Free Blogger Templates by DeluxeTemplates.net
Wordpress Theme by EZwpthemes