Question

A volume of 30.0mL of a 0.810\it M \rm HNO_3 solution is titrated with 0.340\it M \rm KOH. Calculate the volume of \rm KOH required to reach the equivalence point

Answer 1

Concepts and reason

The concept used to solve this problem stoichiometry of balance reaction.

Stoichiometry of balance reaction indicates the relationship between reactant and products of any chemical reaction.

Fundamentals

A balanced chemical equation is an equation that contains same number of atoms of each element on each side of reaction.

Acid-base neutralization reaction:

When an acid reacts with a base to give water and an ionic salt, the reaction is known as Acid-base neutralization reaction.

For example:

Molarity:

The number of moles of solute per liter of solution is known as molarity of the solution. It symbolized by . Molarity of any solution is a ratio of moles of solutes per liter of solution. It expressed by the following formula:

Equivalent point:

Equivalent point is a point of acid-base titration where acid and base present in the stoichiometrically equivalent amount.

Indicator:

Indicator of acid-base titration is a compound that changes color according to changes of solution. In general the color of indicator of acid-base titration changes when the acidic solution becomes basic or basic solution becomes acidic.

End point:

End point of acid –base titration is a point at which the acidic solution becomes basic or basic solution becomes acidic means at this point the indicator changes its color. In general to determinate the end point we use an indicator in acid-base titration.

To calculate the number of moles uses the following expression:

The balance reaction between and is as follows:

According to the problem; there are of a solution is titrated with.

‎ First calculate the moles of as follows:

In this reaction reacted with Therefore will react with the following number of :

Now calculate the volume of as follows:

Now change the unit of volume from L to mL as follows:

Ans:

Thus, to reach equivalence point, 71.5 mL of is required.