Question

What is the difference between a direct titration and a back titration? (Select all that apply.)

In a direct titration, a known excess of reagent that reacts with analyte is used. The excess is then measured with a second titrant.

In a back titration, titrants react directly with analyte.

In a direct titration, titrants react directly with analyte.

In a back titration, a known excess of reagent that reacts with analyte is used. The excess is then measured with a second titrant.

Answer 1

Concepts and reason

Titration is the laboratory methods of quantitative chemical analysis which is used to determine the concentration of a known analyte or chemical component present in the sample mixture.

Fundamentals

Direct titration

By this method, concentration of the unknown determine directly. In this method, titrants (filled in burette) will reacts with directly with the analyte.

Back titration

In this method, titrants will reacts with indirectly with the analyte. By this method, the concentration of known compound is measured to determine the remaining amount of a known compound with known concentration.

The direct titration involves, the chemical reaction between titrant (a compound with known concentration) and the unknown compound present in the sample solution.

Therefore, this statement is false.

In back titration, titrant does not reacts with analyte or chemical compound directly due to excess amount of titrant.

Therefore, this statement is false.

This is regular method to determine the concentration of a unknown compound present in the sample solution. In direct titration, titrant (a compound with known concentration) filled in a burette and the sample solution is filled into the conical flask, so we will directly added titrant in the sample solution drop-by-drop and also add some drops of indicator which will help to indicates the end point.

Therefore, this statement is true.

In the back titration, the concentration of an unknown compound is determine by using an excess amount of a compound with the known concentration.

Therefore, this statement is true.

Ans:

The statement (I) is ‘False’.

The statement (II) is ‘False’.

The statement (III) is ‘True’.

The statement (IV) is ‘True’.