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Which of the following will produce a buffer solution? Explain your reasoning.

1. mixing 100 mL of 0.10 M HCl with 100 mL of 0.10 NaF
2. mixing 50 mL of 0.10 M HCl with 100 mL of 0.10 NaF
3. mixing 100 mL of 0.10 M HF with 100 mL of 0.10 HCl
4. mixing 100 mL of 0.10 M HF with 50 mL of 0.10 NaOH
5. mixing 100 mL of 0.10 M NaF with 50 mL of 0.10 NaOH