Materials

• Data collection system
• pH sensor
• Drop counter and micro stir bar
• Magnetic stirrer
• Buret, 50-mL
• Graduated pipet with rubber bulb, 25-mL
• Beaker, 100-mL (2)
• Beaker, 25-mL (2)
• Clamp, right-angle
• Clamp, buret
• Ring stand
• Parafilm or aluminum foil
• Funnel
• Hydrochloric acid, unknown concentration, 70 mL
• Sodium hydroxide (NaOH), standardized by student in previous activity, 100 mL
• Buffers, pH 4 and pH 10, 10 mL
• Deionized water, 100 mL
• Wash bottle with deionized water
• Cotton swab or tissue