Question

Specify which indicator or indicators you would use for the following titrations:

a. HCOOH versus NaOH
b. HCl versus KOH
c. HNO3 versus CH3NH2

Answer 1

The indicators used for the titrations are phenolphthalein, bromothymol blue, and methyl orange.

Step-by-step explanation:

Indicator Selection for Titrations

In titrations, the choice of indicator depends on the type of titration being performed. For the titration of HCOOH with NaOH, phenolphthalein can be used as the indicator. For the titration of HCl with KOH, bromothymol blue can be used as the indicator. For the titration of HNO3 with CH3NH2, methyl orange can be used as the indicator.

Answer 2

1. Phenolphthalein

2. Phenolphthalein

3. Methyl orange

Step-by-step explanation:

Different indicators are used by knowing the relative strength of the acid and the bases I.e whether the acid is strong or weak, so also the base.

The following answers are obtainable:

1. Phenolphthalein

We use this indicator for a weak base and a strong acid. Formic acid is a weak organic acid while sodium hydroxide is a strong base

2. Phenolphthalein

We use this indicator because we are dealing with a strong acid and a strong base. Hydrochloric acid is a strong acid while potassium hydroxide is a strong base

3. Methyl orange

This is because we are dealing with a strong acid and a weak base