State whether each of the following statements is true or false. Justify your answer in each case. (a) NH3 contains no OH- ions, and yet its aqueous solutions are basic

Verified step by step guidance

1. Identify the chemical formula and structure of ammonia (NH3). Ammonia is a compound consisting of nitrogen and hydrogen atoms.
2. Understand the behavior of ammonia in water. When NH3 is dissolved in water, it reacts with water molecules to form ammonium ions (NH4+) and hydroxide ions (OH-).
3. Write the chemical equation for the reaction of ammonia with water: NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq).
4. Analyze the presence of OH- ions. From the reaction, it is evident that OH- ions are produced, which are responsible for the basic nature of the solution.
5. Conclude that the statement 'NH3 contains no OH- ions, and yet its aqueous solutions are basic' is false because the basic nature of NH3 solutions is due to the presence of OH- ions produced in the reaction with water.

Key Concepts

Ammonia and Basicity

Ammonia (NH3) is a weak base that can accept protons (H+) from water, leading to the formation of ammonium ions (NH4+) and hydroxide ions (OH-) in solution. This reaction increases the concentration of OH- ions, which is responsible for the basic nature of the solution, even though NH3 itself does not contain OH- ions.

Equilibrium in Aqueous Solutions

In aqueous solutions, a dynamic equilibrium exists between the reactants and products of a chemical reaction. For ammonia, the equilibrium between NH3, NH4+, and OH- illustrates how the presence of NH3 can lead to the generation of OH- ions, contributing to the basicity of the solution despite NH3 lacking OH- in its molecular structure.

pH and Basic Solutions

The pH scale measures the acidity or basicity of a solution, with values below 7 indicating acidity and values above 7 indicating basicity. A basic solution has a higher concentration of OH- ions, which raises the pH. Therefore, the presence of OH- ions, even if generated from NH3, is what classifies the solution as basic.