Question

Consider a buffered solution containing CH₃NH₃Cl and CH₃NH₂. Which of the following statements are true concerning this solution? (K_a for CH₃NH₃⁺ = 2.2 × 10^-11).

(Select all that apply.)

A solution consisting of 2.5 M CH₃NH₃Cl and 2.5 M CH₃NH₂ would have a higher capacity than one containing 0.5 M CH₃NH₃Cl and 0.5 M CH₃NH₂.

If NaOH were added to the initial buffered solution, then the [CH₃NH₂] would increase.

Adding more [CH₃NH₃Cl] to the initial buffer solution will decrease the pH.

If [CH₃NH₂] < [CH₃NH₃⁺], then pH is larger than the pK_a value.

A solution consisting of 0.10 M CH₃NH₃Cl and 0.10 M CH₃NH₂ would have a higher capacity than one containing 1.0 M CH₃NH₃Cl and 1.0 M CH₃NH₂.

Answer 1

Answer:-

The true statements are the following,

A solution consisting of 2.5 M CH₃NH₃Cl and 2.5 M CH₃NH₂ would have a higher capacity than one containing 0.5 M CH₃NH₃Cl and 0.5 M CH₃NH₂.

Because it will more strong acid or base to lose its buffer action as it has high concentration.

If NaOH were added to the initial buffered solution, then the [CH₃NH₂] would increase.

because NaOH will convert the CH₃NH₃⁺ into CH₃NH₂.

Adding more [CH₃NH₃Cl] to the initial buffer solution will decrease the pH.

As it will increase the concentration of H₃O⁺ ion.