Question Video: Writing the Balanced Net Ionic Equation for the Reaction between the Ammonium Ion and Sodium Hydroxide Chemistry

What is the balanced net ionic equation for the reaction between an ammonium ion and sodium hydroxide?

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Video Transcript

What is the balanced net ionic equation for the reaction between an ammonium ion and sodium hydroxide?

The presence of ammonium ions can be tested using sodium hydroxide. For example, a dilute sodium hydroxide solution can be added to an unknown solution and the results observed. If the solution contains ammonium ions, a few small bubbles will form. The solution may need to be heated slightly to initiate the reaction. A gas is produced if ammonium ions are present. The gas that is being released is ammonia gas, which has the chemical formula NH3.

If enough ammonia gas is formed, we may be able to detect it by its pungent odor. However, ammonia, like many other gases in the laboratory, is toxic in large quantities, so smelling a gas to detect it is not advisable. A safer way to test for the presence of ammonia gas is to hold a piece of moist red litmus paper near the mouth of the test tube. If the litmus paper turns blue, then we know that the ammonia gas is forming an alkali on the paper.

If we know that the reaction between ammonium ions and hydroxide ions forms ammonia gas, we can begin to write a balanced net ionic equation. We can deduce that the second product of this reaction will be water. The net ionic equation looks like this. A net ionic equation is a simplified ionic equation that only shows the species involved in the chemical reaction. Any other ions present in the solution would be spectator ions and are not necessary to write in a net ionic equation.

The ionic equation for this reaction is shown. In this case, the sodium cations from sodium hydroxide are not active participants in the reaction and are thus spectator ions. Therefore, the balanced net ionic equation for the reaction between an ammonium ion and sodium hydroxide is NH4+ aqueous reacts with OH− aqueous to form NH3 gas and H2O liquid.