A Buffer Is Prepared by Combining 25 ML of 0

question 4

Multiple Choice

A buffer is prepared by combining 25 mL of 0.50 M NaF(aq) with 25 mL of 0.25 M HCl.What is the pH of the buffer? (K_a (HF) = 6.9 × 10−⁴)

• A) 3.16
• B) 3.50
• C) 4.12
• D) 4.60
• E) 7.11

---

Definitions:

Lymphatic System

A subsystem of the cardiovascular system; returns excess interstitial fluid (lymph) to the circulation; defends the body against disease organisms.

Interstitial Fluid

The fluid that surrounds the cells in tissues and is exchanged with the blood, providing nutrients and removing waste materials.

Pacemaker

A device implanted in the chest to regulate the heartbeat.

Atrioventricular Node

A part of the cardiac conduction system that coordinates the top heart chambers (atria) contraction with the bottom chambers (ventricles) ensuring a synchronized heartbeat.