An acidic buffer is obtained on mixing :
1. 100 mL of 0.1 M CH3COOH and 100 mL of 0.1 M NaOH.
2. 100 mL of 0.1 M HCl and 200 mL of 0.1 M NaCl.
3. 100 mL of 0.1 M HCl and 200 mL of 0.1 M CH3COONa.
4. 100 mL of 0.1 M CH3COOH and 200 mL of 0.1 M NaOH.
An aqueous solution of 1M NaCl and 1M HCl is :
1. not a buffer but pH < 7
2. not a buffer but pH >7
3. a buffer with pH <7
4. a buffer with pH >7