To make student understand concept of Neutralization Reaction via simulation which is a process that occurs when an acid and a base interacts.


A new chemical is formed in a neutralization reaction. This is called salt. Salt can be neutral, acidic, or basic in nature. In this process, heat evolution results in the production of salt and water.

  • Acid + BaseSalt + Water (Heat is evolved)

  • The chemical reaction(s) showing neutralization reaction with different acid and bases as precursor(s) are listed below as:

  • HCl + NaOH NaCl+ H2O
  • HCl + KOH KCl +H2O
  • HCl + Mg(OH)2 MgCl2 + 2H2O
  • HCl + Fe(OH)3 FeCl3 + H2O


    Neutralization reactions are significant in daily life as they control the solution's pH. The pH of the solution is important since it help one know how basic and how acidic the solution is.


    • Add diluted hydrochloric acid to one-fourth of a test tube. And note down its color.
    • And also note down the color of phenolphthalein indicator solution. To the acid, add a few drops of the phenolphthalein indicator. Now, lightly shake the test tube.
    • Use a dropper to add a drop of sodium hydroxide to the acidic solution. Gently shake the tube.
    • Stirring constantly, keep adding drops of the sodium hydroxide solution until the pink color just appear.
    • Now add one or more drops of diluted hydrochloric acid. The solution again becomes colorless.
    • Add sodium hydroxide solution one more time. The solution again become pink in color.
    • It is clear that phenolphthalein turns a solution pink when it is basic, but colorless when an acidic solution is present.
    • When an acidic solution and a basic solution are combined, the effects of each solution are neutralized.
    • The properties of acid and base are destroyed when they are combined in the proper proportions. The resulting solution is neither acidic nor basic.
    • After neutralization, immediately touch the test tube.
    • When a reaction of neutralization occurs, heat is always produced, or evolved.
    • The temperature of the reaction mixture is increased by the heat that is evolved.
    • The color change indicates the neutralization reaction.

    • Add few drops of dilute HCl to fill one-fourth of the test tube. Note the colour.
    • Note the colour of Phenolphthalein indicator and add 4 drops of it to the test tube. Shake the test tube gently.
    • Add a drop of NaOH to the test tube. Shake the test tube gently.
    • Add more drops of NaOH and shake test tube, till pink color just appears.
    • Add 1 or more drops of dilute HCl. Note the vanishing of pink color.
    • Add one more drop of NaOH and note the solution turning pink again. End of the experiment! Note that heat is evolved as a result of the reaction of acid & base.

    • Guidelines
      Click on beaker to move dropper to or from test tube.
      Click on dropper to put a drop of the substance.
      Click on vortex shaker button to gently shake the test tube.
      Note: Max limit of liquid in test tube upto holder arm (68 drops)


    1. When an acid or base react in a neutralization reaction, what product are formed.

    2. The neutralization reaction is reaction between

    3. A solution of pH 7 is

    4. How many moles of hydrogen ions will react with 1 mole of hydroxide ions during an acid-base neutralization reaction?

    5. Neutralizations reactions are

    6. A neutral solution contains

    7. What will be the salt of the given reaction? Zn(OH)2 + HNO3 ->

    8. Neutralization reaction is a


    Category Theme Activity
    Chemistry Reaction Chemistry Neutralization Reaction

    Activity Type


    Principal Investigator (s)

    Dr. Anuj Krishna & Prof. (Dr). Rina Sharma

    CSIR-National Physical Laboratory


    Kaphi, Anuj Krishna & Prof. (Dr). Rina Sharma and Team JIGYASA, CSIR-NPL