Question

Place the following molecules in the order smallest to biggest

Answer 1

NH₂⁻<NH₃<NH₄⁺

Step-by-step explanation:

Hello.

In this case, regarding the molecules:

NH₄⁺, NH₃ and NH₂⁻.

Which are ammonium, ammonia and amide, in order to rank them in terms of how big the angles are, we need their molecular geometry as shown on the attached picture. As you can see, the geometry of ammonium is tetrahedral with an angle between H bonds of 109.5°, the geometry of ammonia is trigonal pyramidal with an angle between H bonds of about 107° and the geometry of amide is bent with angles of 104.5°.

Therefore the order from smallest to biggest is: NH₂⁻<NH₃<NH₄⁺.

Best regards.