Reagents – Dilution

How to dilute acids and bases.

Dilution of acids are exothermic reactions, proper precautions are to be taken while diluting acids. Wear goggles at all times, aprons and gloves would add an extra layer of protection.

Acids:

Concentration of acids available

  • HCl 12 M
  • H2SO4 18 M
  • HNO3 16 M

Preparation of 1 M HCl

  • To prepare 1 Liter of 1 M HCl measure out 83 ml of 12 M concentrated acid in a fume cupboard and add it to 917 ml of distilled water. Using a magnetic stirrer to mix the acid would be a good idea, if that is not available use a glass rod.

Preparation of 1 M H2SO4

  • To prepare 1 Liter of 1 M H2SO4 measure out 56 ml of 18 M concentrated acid in a fume cupboard and add it to 944 ml of distilled water. Using a magnetic stirrer to mix the acid would be a good idea. The dilution of sulfuric acid is exothermic so add small quantities of the acid to water – Extra care should be taken while diluting sulphuric acid.

Preparing 1M HNO3

  • To prepare 1 Liter of 1 M HNO3 measure out 63 ml of 16 M concentrated acid in a fume cupboard and add it to 937 ml of distilled water. Using a magnetic stirrer to mix the acid would be a good idea, Nitric acid is an oxidizing acid, if it comes in contact with your skin it will turn yellow due to nitration. The skin will eventually be replaced.

Preparation of 1 M NH4OH

  • Ammonium hydroxide is volatile and pungent make sure the fume cupboard exhaust is turned on before you attempt to dilute the base.
  • To prepare 1 Liter of 1 M NH4OH measure out 63 ml of 16 M ammonium hydroxide to 937 ml of distilled water. Using a magnetic stirrer to mix the base, if that is not available use a glass rod. Put the caps on the bottles right away and transfer the prepared solution to an appropriate glass ware and keep the lid closed.