Question

8) Determine whether mixing each pair of the following results in a buffera. 100.0 mL of 0.10 M NH3 with 100.0 mL of 0.15 MNH4Cl b. 50.0 mL of 0.10 M HCL with 35.0 mL of 0.150 M NaOHc. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOHd. 175.0 mL of 0.10 M NH3 with 150.0 mL of 0.12 M NaOH

Answer 1

Answer:

a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.

c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.

Explanation:

A buffer system is formed in 1 of 2 ways:

• A weak acid and its conjugate base.

• A weak base and its conjugate acid.

Determine whether mixing each pair of the following results in a buffer.

a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.

YES. NH₃ is a weak base and NH₄⁺ (from NH₄Cl ) is its conjugate base.

b. 50.0 mL of 0.10 M HCl with 35.0 mL of 0.150 M NaOH.

NO. HCl is a strong acid and NaOH is a strong base.

c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.

YES. HF is a weak acid and it reacts with NaOH to form NaF, which contains F⁻ (its conjugate base).

d. 175.0 mL of 0.10 M NH₃ with 150.0 mL of 0.12 M NaOH.

NO. Both are bases.