Which of the following compounds would decrease the pH of solution?

• A. SrBr₂
• B. KSH
• C. NaN₃
• D. NiP
• E. Hg₂Cl₂

Answer: (D)

Verified step by step guidance

1. Identify the ions present in each compound. For LiC2H3O2, the ions are Li+ and C2H3O2-. For C6H5NH3Br, the ions are C6H5NH3+ and Br-.
2. Determine the nature of each ion. Li+ is a cation from a strong base (LiOH), and C2H3O2- is the acetate ion, which is the conjugate base of acetic acid (a weak acid). C6H5NH3+ is the conjugate acid of aniline (a weak base), and Br- is the bromide ion, which is the conjugate base of hydrobromic acid (a strong acid).
3. Analyze the behavior of the ions in water. Li+ does not affect the pH significantly, while C2H3O2- can accept protons, making the solution basic. C6H5NH3+ can donate protons, making the solution acidic, while Br- does not affect the pH significantly.
4. Conclude the solution's nature based on the dominant ion effect. For LiC2H3O2, the basic nature of C2H3O2- dominates, resulting in a basic solution. For C6H5NH3Br, the acidic nature of C6H5NH3+ dominates, resulting in an acidic solution.
5. Summarize the findings: LiC2H3O2 creates a basic solution, and C6H5NH3Br creates an acidic solution.