Define pH or pH scale.
admin Sorensen in 1909 discovered a new tern for expressing the concentration of hydrogen ions known as pH or pH scale. The pH of a solution is defined as: The negative…
Calculate the dissociation constant of conjugate base of HF, Ka = 6.8 x 10-4.
We know that HF < ———–> H+ + F– Ka (acid) x Kb (conjugate base) = Kw = 1.0 x 10-14 Ka = 6.8 x 10-4 (given) Kb (F–) =…
What do you mean by Polytrophic acids and bases?
Bronsted acids which can donate more than one proton are called Polytrophic acids or polybasic acids. For example, oxalic acid and sulphuric acid have two ionizable protons per molecule of…
A saturated solution of H2S in water has concentration of approximately 0.10 M. What is the pH of this solution and equilibrium concentrations of H2S, HS– and S2-? Hydrogen sulphide is a diprotic acid and its dissociation constants are Ka1 = 9.1 x 10-8, Ka2 = 1.3 x 10-13 mol L-1 respectively.
The second dissociation constant is very small than the first dissociation constant and therefore, the concentration of H3O+ is obtained only from the first dissociation constant: H2S + H2O <…
What do you mean by Hydrolysis?
Hydrolysis is the interaction of anion or cation of the salt with water to produce an acidic or basic solution. For example: An aqueous solution of copper sulphate is acidic…
Derive the relationship between Kh, Kw, Ka.
Let us consider the concentration of water remains constant, the equilibrium constant for hydrolysis reaction called hydrolysis constant may be written as: Kh = / ………………………………. (1) The following equilibrium…
What do you mean by Indicators?
Indicators are the substances which indicate by change in color, the completion of the chemical reaction. We know that litmus solution is red in the acidic region and blue in…
What do you mean by titration and what do you understand by Stoichiometric point?
The titration of an acid with a base or of a base with an acid is very convenient method for measuring quantities of the substances in the solution. This process…
Define Mixed Indicators?
With ordinary acid base indicators, the color change is not sharp and abrupt, but it extends over 2 units of pH. However, sometimes, it is desirable to have sharp color…
Define Universal Indicators?
A Universal Indicator is defined as a mixture having many indicators of wide pH range. To obtain universal indicators, many indicators are mixed( though it behave as a single indicator)…