Self Ionization Of Water Equation

What is Ionization?

Ionisation is defined as the process by which an atom or molecule gains or loses a positive or negative charge as a result of chemical changes. An ion is an electrically charged cantlet or molecule that results. If the ion has a negative charge, it is chosen an anion; if it has a positive charge, information technology is called a cation.

The basic ionisation reaction tin can be represented as follows:

1000 → Yard⁺ + e^–

Ionisation can occur as a effect of the loss of an electron in collisions with subatomic particles, collisions with other atoms, molecules, and ions, or interactions with electromagnetic radiations.

Table of Contents

• Amphiprotic Nature of Water
• Self Ionization of H2o
• Pure H2o's Ion-Production Constant
• Relationship amid pH, pOH, and pKw
• Frequently Asked Questions – FAQs

Amphiprotic Nature of H2o

Due to its highly polar structure, liquid water can either act as an acid (by donating a proton to a base) or a base (by using a lone pair of electrons to have a proton).

Equally bases:

When a strong acrid similar HCl dissolves in h2o, information technology separates into chloride ions (Cl^–) and protons (H⁺). In turn, the proton reacts with a water molecule to form the hydronium ion (H₃O⁺):

HCl (aq) + H₂O(l) → H₃O⁺(aq) + Cl^–(aq)

The acrid in this reaction is HCl, and the base of operations is water, which accepts an H⁺ ion.

Every bit acids:

Water tin also act as an acrid. H₂O donates a proton to NH₃, which acts as a base, in this equilibrium reaction:

H₂O(aq) + NH₃(aq) ⇆ (NH₄)⁺ + OH^–

Water is thus called amphiprotic because it can deed as an acid or a base depending on the nature of the other reactant.

Self Ionization of Water

Water will self-ionize to a very small extent under normal atmospheric condition. The reaction in which a water molecule donates one of its protons to a neighbouring h2o molecule, either in pure water or in an aqueous solution, is referred to as the cocky-ionization of h2o.

In an autoionization process, 1 water molecule tin can react with some other to course an OH^– ion and an H₃O⁺ ion:

2H_iiO(l) ⇆ H_threeO⁺(aq) + OH^–(aq)

Pure Water's Ion-Product Constant

This reaction's equilibrium abiding K tin be written every bit follows:

\(\brainstorm{array}{50}K= \frac{\left [ H_{three}O \right ]^{+}\left [ OH \right ]^{-}}{\left [ H_{2}O \correct ]^{two}}\end{array} \)

Every bit a result, the number of dissociated water molecules is very small.

The autoionization reaction'south equilibrium is far to the left, with few water molecules dissociate. As a result, the autoionization reaction leaves [H₂O] essentially unchanged and tin can exist treated as a constant. By incorporating this constant into the equilibrium expression, we can rearrange the equilibrium constant equation to define a new equilibrium constant, the liquid h2o ion-product abiding (K_w):

\(\begin{array}{l}M= \frac{K_{w}}{\left [ H_{two}O \right ]^{2}}\end{array} \)

\(\brainstorm{array}{l}K_{w}= \left [ H_{3}O \right ]^{+}\left [ OH \right ]^{-}\end{assortment} \)

The concentrations of the hydronium ion and the hydroxide ion are equal when pure liquid h2o is in equilibrium with hydronium and hydroxide ions at 25°C:

H_threeO⁺(aq) = OH^–(aq) = 1.003 × x^-7 mol/Fifty

Therefore,

\(\brainstorm{array}{l}K_{westward}= ane.003 \times 10^{-seven}mol Fifty^{-1} \times i.003 \times 10^{-seven}mol L^{-1}\end{array} \)

\(\begin{assortment}{l}K_{due west}= one.006 \times 10^{-seven}mol^{2} L^{-2} \stop{array} \)

At 25°C, the equilibrium constant One thousand_west applies to any aqueous solution, non just pure water.

• The hydronium ion and the hydroxide ion concentrations are equal in pure water, so the solution is neutral.
• If [H₃O⁺] > [OH^–], the solution is acidic.
• If [H_iiiO⁺] < [OH^–], the solution is bones.

The H₃O⁺ concentration in an aqueous solution is a quantitative measure of acidity: the higher the H₃O⁺ concentration, the more acidic the solution. In contrast, the college the concentration of OH^–, the more basic the solution.

Relationship amid pH, pOH, and pK_w

The pH scale is a concise way of describing the concentration of H₃O⁺ in a solution, and thus its acidity or basicity.

The equilibrium abiding K_{due west} is expressed equally:

\(\brainstorm{array}{l}K_{west}= \left [ H \right ]^{+}\left [ OH \right ]^{-}\end{array} \)

Taking the negative logarithm of both sides of the equation:

\(\brainstorm{array}{l}-log K_{w}= -log (\left [ H \right ]^{+}\left [ OH \correct ]^{-})\end{array} \)

\(\begin{array}{l}-log K_{w}= -log\left [ H \correct ]^{+} + -log\left [ OH \right ]^{-}\end{assortment} \)

pK_w = pH + pOH

Since, pK_w = 14

pH + pOH = fourteen.

At 25°C,

pH + pOH = 14.00 for any neutral solution with pH = pOH = 7.

Ofttimes Asked Questions on Ionization of Water

What practice you hateful by the term "water auto-protolysis"? What is the significance of this?

The procedure of self-ionization of water molecules to produce hydronium ion and hydroxide ion is known equally auto-pyrolysis of water.

2H_iiO(50) ⇆ H₃O⁺(aq) + OH^–(aq)

The reaction represents water's amphoteric nature. It can human action as both a base and an acid. I water molecule donates an electron, while another accepts an electron.

What exercise y'all empathise past the amphiprotic nature of water?

Liquid h2o, due to its highly polar structure, can either deed as an acid (by donating a proton to a base) or a base of operations (by using a lone pair of electrons to accept a proton).

This is the amphiprotic nature of h2o.

How many ions does water take?

H2o (H₂O) is decomposed into Hydrogen Ions (H⁺) and Hydroxyl Ions (OH^–). pH is neutral (seven) when there are equal parts of hydrogen ions (H⁺) and hydroxyl ions (OH^–), resulting in a 1:ane ratio.

What is the relationship between pH, pOH, and pK_w?

The relationship between pH, pOH, and pK_west is:

pK_west = pH + pOH = 14.

What is the ion-product abiding of liquid water?

Kw denotes the ion-product abiding of liquid h2o and it tin can be expressed every bit:

Thousand_w = [H₃O]⁺ [OH]^–

At 25℃, K_west = 1.006 × 10^-xiv.

Self Ionization Of Water Equation,

Source: https://byjus.com/chemistry/ionization-of-water/

Posted by: heiserluelf1998.blogspot.com

Share this post