Which of the following gives a buffer solution when equal volumes of the two solutions are mixed? (a) 0.10 M HF and 0.10 M NaF (b) 0.10 M HF and 0.10 M NaOH (c) 0.20 M HF and 0.10 M NaOH (d) 0.10 M HCl and 0.20 M NaF

Verified step by step guidance

1. Identify the components needed for a buffer solution: a weak acid and its conjugate base, or a weak base and its conjugate acid.
2. Analyze option (a): 0.10 M HF (a weak acid) and 0.10 M NaF (provides F⁻, the conjugate base of HF). This combination can form a buffer solution.
3. Analyze option (b): 0.10 M HF (a weak acid) and 0.10 M NaOH (a strong base). This will result in a neutralization reaction, not a buffer.
4. Analyze option (c): 0.20 M HF (a weak acid) and 0.10 M NaOH (a strong base). The NaOH will partially neutralize the HF, potentially forming a buffer if the weak acid remains in excess.
5. Analyze option (d): 0.10 M HCl (a strong acid) and 0.20 M NaF (provides F⁻). Since HCl is a strong acid, it will not form a buffer with NaF.