Arrange the solutions in order of increasing acidity. NaCl, NH₄Cl, NaHCO₃, NH₄ClO₂, NaOH

Acidity refers to the concentration of hydrogen ions (H+) in a solution, which determines its pH level. A lower pH indicates a more acidic solution, while a higher pH indicates a more basic solution. Understanding the pH scale is essential for comparing the acidity of different solutions.

Salt hydrolysis occurs when a salt dissolves in water and reacts with water to produce an acidic or basic solution. For example, ammonium chloride (NH4Cl) can release H+ ions, making the solution acidic, while sodium bicarbonate (NaHCO3) can produce OH- ions, making the solution basic. This concept is crucial for determining the acidity of the given salts.

Strong acids and bases completely dissociate in water, while weak acids and bases only partially dissociate. For instance, NaOH is a strong base that fully dissociates, leading to a higher pH, whereas NH4Cl is derived from a weak acid (NH4+) and a strong base (Cl-), resulting in a more acidic solution. This distinction is vital for ranking the acidity of the solutions.