Chemistry, asked by siya125, 6 months ago

Derive the expression of ionic product of water.

Answer it fast okay.. ​

Answers

Answered by saiharsha85
1

Answer:

This page explains what is meant by the ionic product for water. It looks at how the ionic product varies with temperature, and how that determines the pH of pure water at different temperatures.

Kw and pKw

The important equilibrium in water

Water molecules can function as both acids and bases. One water molecule (acting as a base) can accept a hydrogen ion from a second one (acting as an acid). This will be happening anywhere there is even a trace of water - it doesn't have to be pure.

A hydroxonium ion and a hydroxide ion are formed.

However, the hydroxonium ion is a very strong acid, and the hydroxide ion is a very strong base. As fast as they are formed, they react to produce water again.

The net effect is that an equilibrium is set up.

At any one time, there are incredibly small numbers of hydroxonium ions and hydroxide ions present. Further down this page, we shall calculate the concentration of hydroxonium ions present in pure water. It turns out to be 1.00 x 10-7 mol dm-3 at room temperature.

You may well find this equilibrium written in a simplified form:

This is OK provided you remember that H+(aq) actually refers to a hydroxonium ion.

Answered by smartykiller
1

Answer:

Hey mate

Explanation:

Here is ur answer...

First of all in short

The product of concentrations of H1 and OH ions in water at a particular temperature is known as ionic product of water. The value of Kw increases with the increase of temperature, i.e., the concentration of H+ and OH- ions increases with increase in temperature. The value of Kw at 25°C is 1 x 10-14.

And now I am giving u the actual derivation of IPW ok.

Pure water is a very weak electrolyte and ionises according to the equation

H2O ↔ H+ + OH-

Applying law of mass action at equilibrium, the value of dissociation constant, K comes to

K = [H+] [OH-

]/[H2O]

or [H+][OH-

] = K[H20]

Since dissociation takes place to a very small extent, the concentration of undissociated

water molecules, [H20], may be regarded as constant. Thus, the product #[H20] gives

another constant which is designated as Kw. So,

[H+][OH-

] = Kw

The constant, Kw, is termed as ionic product of water.

The product of concentrations of H1 and OH ions in water at a particular temperature is

known as ionic product of water. The value of Kw increases with the increase of

temperature, i.e., the concentration of H+ and OH- ions increases with increase in

temperature.

Temperature (°C) Value of Kw

0 0.11 x 10-14

10 0.31 x 10-14

25 1.00 x 10-14

100 7.50 x 10-14

The value of Kw at 25°C is 1 x 10-14. Since pure water is neutral in nature, H+ ion

concentration must be equal to OH- ion concentration.

[H+] = [OH˜] = x

or [H+][OH-

]=x2

= 1 x 10-14

or x = 1 x 10-7 M

or [H+] = [OH-

] = 1 × 10-7 mol litre-1

This shows that at 25°C, in 1 litre only 10-7 mole of water is in ionic form out of a total of

approximately 55.5 moles.

HOPE ITS HELP U ❤️

SMARTYKILLER ❤️✌

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