Glycine pH and Charge Properties

The video tutorial explains the titration process of glycine, focusing on how the addition of H+ and OH- ions affects the pH of the solution. Initially, in an acidic environment, glycine has a net positive charge. As NaOH is added, the carboxyl group of glycine donates H+ ions, stabilizing the pH. Once all carboxyl groups have donated H+, the pH rises sharply. At the isoelectric point, glycine has both positive and negative charges. Further addition of OH- ions increases the pH, and at pH 9.6, the ammonium group donates H+ ions, stabilizing the pH again. Eventually, glycine has a net negative charge.

What is the initial charge of glycine in an acidic environment?

• Net positive charge

• Zwitterionic

• Net negative charge

• Neutral

What effect does the addition of NaOH have on the pH of the solution initially?

• Increases pH

• Decreases pH

• Causes pH to fluctuate

• No effect

At what pH does the carboxyl group of glycine start donating its H+ ion?

• 9.6

• 2.3

• 1.0

• 7.0

What happens to the pH when the carboxyl group of glycine donates its H+ ions?

• It fluctuates

• It increases

• It remains constant

• It decreases

What is the charge of glycine when it becomes a zwitterion?

• Both positive and negative charge

• Neutral

• Net positive charge

• Net negative charge

What happens to the pH when hydroxyl ions are added after all carboxyl groups have donated their H+ ions?

• It decreases

• It remains constant

• It increases suddenly

• It fluctuates

What pH level is reached when the ammonium group of glycine starts donating its H+ ion?

• 2.3

• 9.6

• 7.0

• 12.0

What is the net charge of glycine after the ammonium group donates its H+ ions?

• Net positive charge

• Zwitterionic

• Neutral

• Net negative charge