Analyse The Concentration Of Hydrogen Ion

           
Chemistry revolves around the reaction amongst ions of different elements. In any chemical reaction, the quantity of unionized molecules together with the ions released from the weak electrolytes’ solution contributes towards the establishment of an equilibrium status. This equilibrium status is known as ionic equilibrium.

To analyse the concentration of hydrogen ion, the factor which is taken into consideration is the concentration of the hydrogen ion which remains present in the solution.

Suppose, if we consider a reaction amongst a conjugate acid and a weak base or even vice versa in the base solvent of water, then the whole mixture will act as a buffer.

Ph= -log[H+].

In the above equation the [H+] is the symbol for the concentration of ion. This ion is contributed in the solution from the acid component. The pH can be basic, neutral and acidic depending on the concentration of [H+] ions in the solution.

The p in the pH is the power of the hydrogen concentration. The H in the pH represents the Hydrogen but for some of the elements, the letter p is used as an abbreviation for power.

The concentration of the [H+] ions in the solution depends on the characteristic of the type of acid used, whether the acid is strong or weak.  The acid which displays the property of being incompletely dissociated in any solution is known as a weak acid. For examples, acetic acid (CH3COOH) and vinegar are the weak acids.

CH3COOH is evidenced to be dissociated as CH3COO- and H+.
Then to find the degree of dissociation it becomes equal to “kac”.

In the above expression, the ka is known as the dissociation constant, C is the concentration of the hydrogen or any concerned element.

Pka = -logka

In the above equation, the terms pka and ka shares and inversely proportional relationship. It very much evident with the given negative sign.

The degree of dissociation is found to be dependent on three factors which are stated below:

• Ostwald’s Dilution Law: This law states that on the process of diluting any solution  the resultant concentration of the whole solution decreases which results in the increment of the degree of dissociation. The new concentration of the solution depends on the extent to which the solution has been diluted. But there are limitations to the fact that only diluting any solution will increase the degree of dissociation.

• Temperature: It is a known fact that dissociation is an endothermic process, that is, it requires heat to undergo the dissociation method. Reaction which has a positive value of hydrogen ion results in the increase of  Keq. The increased temperature is found to be associated with the increment of Keq. As a result of which, the product’s concentration increases and therefore, the degree dissociation is also found to be increased. The solution of a conjugate acid base and a weak acid is known as a pH buffered solution. 

Overall, it has been found that CH3COOH as well as the sodium acetate is also used as a pH buffered solution to a great extent. The solution is prepared by adding            5.772g of the sodium acetate with the measure of 1.778g of the acetic acid in the distilled water.

pH adjustment is done with the help of hydrochloric acid or HCL. If there remains unavailability of the HCL acid, which is a strong acid, then a pair of a weak acid NH3 and a conjugate weak base NH4OH is supposed to be used.

The general principle of the acid – Base titration is the process in which the acid and the base will be summed up together.

While reacting with each other, it will result in the initiation of the neutralization reaction. The neutralization reaction, as the name suggests, neutralizes the charges released in the solution. This results in the conversation of the pH of the solution.

As the charges released in the solution is neutralized that means the pH will be pushed towards being neutral.

The process of acid-base titration involves the use of an indication which changes the colour of the solution against which the titration is being done. The colour change indicates the change in the pH. The indicator used in this situation is phenolphthalein. The end point is noted when the colourless solution turns to pink. The unknown concentration of the acid can be done by using the equation:

M1V1 = M2V2.

In the above equation,
M1 denotes the molarity of an unknown acid which is to be found out in the titration process as in this situation.
M2 denotes the molarity of the known acid
V1 represents the volume of the acid, which is used in the experiment.
V2 represents the volume of the base, which is used in the experiment.

The process is a quantitative evaluation for the determination of the concentration of a concerned acid as well as the base by using the process of neutralization of the solution with the help of a standard solution. The standard solution is prepared with the help of a base and an acid whose concentration remains unknown.

The use of an indicator solution for noting the colour change, signifying the change of the Ph, is done to observe the progress of the titration method.

The use of indicators like phenolphthalein, methyl orange etc are based on colour change of the solution being titrated against it. Phenolphthalein works by changing the colourless solution to pink, methyl orange indicates the change of pH with the change of colour from red to yellow. It is advantageous to use a physical aspect for noting down the change in pH as it decreases the labour and remains visually appealing also.

The efficiency displayed by a buffer confounding around the resistance to the change in pH is a characteristic of buffer capacity. In any solution, a buffer can act as a repelling agent against the slight change in pH, due to the addition of acid or an alkali to the solution. The buffer capacity is able to determine the ability of any solution which tries to throw resistance in the changes of the pH.

This is principally done by absorbing [OH-] or [H+] ions. In a certain known pH, the capacity of the buffer to resist the change becomes maximum as at the ratio of 1:1 is the best measurement for the preparation of the buffer solution.

pH = pKa,      
from the above equation, it can be briefed that the concentration of the acidic ions is equal to the concentration of the basic ion of the concerned buffer system. This mentioned property is used to measure the ability of the buffer for repelling the change in the pH of the buffer. The number or quantity of moles of a base or an acid when mixed with 1 litre of a buffer system then the pH change accompanied by this act will be 1.

Any solution, which has the ration of concentration of the salt to base or the acid used accordingly ranges in a scale of 1 to 10, will behave as the buffer system.
pH = pKa + log
pH =pKa + 1
pH = pKa – 1

As it is known that dissociation of water requires heat energy or is an endothermic process, the increment of the temperature results in the increment of the kw.

At the temperature of 25 degrees Celsius,
If, pH = pOH, then the solution is neutral and shows the reading of 7
If pH< 7 or pOH> 7 then the solution is said to be acidic
If pH> 7 or POH< 7 then the solution is said to a basic solution.
Ionic product of the universal solvent, water in the state of equilibrium remains steady and therefore, it depends on the temperature or heat being applied to it for the change in pH.

It is to be remembered, that the nature of acid and base are very critical for any solution so as to determine the concentration of ion. The strong acids contribute more to the hydrogen concentration of the solution and weak acid less. Same goes with the base but the ions here is the hydroxyl ion. Increase in the hydrogen ion concentration results in the decrease of pH. To maintain the neutrality of the solution, buffer system is used. In the solution system with buffer, the buffer can repel the change or make slight pH changes. The change is noted with the help of an indicator and therefore, the unknown concentration of hydrogen ion is measured.