The mixture that will produce a buffer solution when mixed in equal volumes is:
| 1. | 0.1 mol dm-3 NH4OH and 0.1 mol dm-3 HCl | 
| 2. | 0.05 mol dm-3 NH4OH and 0.1 mol dm-3 HCl | 
| 3. | 0.1 mol dm-3 NH4OH and 0.05 mol dm-3 HCl | 
| 4. | 0.1 mol dm-3 CH3COONa and 0.1 mol dm-3 NaOH | 
 
                    
                    © 2025 GoodEd Technologies Pvt. Ltd.