Question

5 A)Which of the following statements is true?

The pH of pure water at room temperature is 7.2.

Buffers are weak acids and bases that are used biologically to maintain the pH of a system.

The dissociation constant equation can be used to determine the ionization state of acids and bases in solution.

The equilibrium constant of a reaction can be used to accurately assess the state of linked reactions in cells.

5 B) Why is phosphoric acid such a biologically important molecule?

It has buffering capacity at pH 5.0, which is important for lysosomal function.

It protects nucleic acids from oxidation and other forms of damage.

It has a high degree of molecular affinity for buffers.

It contains three distinct hydrogen atoms that dissociate at different pH values and, therefore, has buffering capacity in three ranges.

Answer 1

5A.Correct answer would be:Buffers are weak acids and bases that are used biologically to maintain the pH of a system.

Reasons:Buffers are solutions which contain weak acid and its conjugate base or just the vice versa ands this helps to resist any pH change of a solution.

5B.Correct answer is :It contains three distinct hydrogen atoms that dissociate at different pH values and, therefore, has buffering capacity in three ranges.

Reason:Phosphoric acid is one of the weak polyprotic acids that donates its protons at different pH to any base that is added to a solution for buffering