Question 1 Report
Which of the following salts when dissolved in water will form a solution that will change blue litmus to red?
The salt that will change blue litmus to red when dissolved in water is NH4Cl. This is because NH4Cl undergoes hydrolysis in water to form NH4OH and HCl. NH4OH is a weak base and will react with water to produce NH4+ and OH- ions. The OH- ions will increase the concentration of hydroxide ions in the solution, making it slightly basic. Litmus paper is an indicator that changes color in response to the pH of a solution. Blue litmus paper turns red in acidic solutions, and since the NH4Cl solution is slightly basic, it will change the blue litmus paper to red.