& x20;What is the role of a buffer in a chemical reaction?

Change the color of the solution

NORCET 1 - 2020

Biochemistry & Nutrition

Easy

What is the role of a buffer in a chemical reaction?

Appeared in: NORCET 1 - 2020

A buffer is a solution that resists changes in pH when an acid or alkali is added.
It works by neutralizing small amounts of added acid or base, thus keeping the pH of the solution stable.
Buffers are typically composed of a weak acid and its conjugate base, or a weak base and its conjugate acid.

Option A: This describes the function of a catalyst, which increases the rate of a reaction by lowering its activation energy.
Option B: This describes the function of an inhibitor, which decreases the rate of a chemical reaction.
Option D: This describes the function of a pH indicator, which changes color to show the pH of a solution but does not stabilize it.

Visual 1: Diagram: The Bicarbonate Buffer System. This visual would show the reversible reaction (H₂CO₃ ⇌ H⁺ + HCO₃⁻) and illustrate how the system neutralizes added H⁺ (acid) by shifting left and added OH⁻ (base) by shifting right, maintaining pH balance.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Function of a chemical buffer and its physiological relevance as background academic context rather than a clinical decision trigger.
Maintaining blood pH between 7.35 and 7.45 is critical for life. Deviations lead to acidosis (pH below 7.35) or alkalosis (pH above 7.45), which can impair enzyme function and cause severe organ damage.
Nurses frequently monitor patients for signs of acid-base imbalances (e.g., through Arterial Blood Gas analysis) and manage conditions that cause them, such as Diabetic Ketoacidosis (DKA), Chronic Obstructive Pulmonary Disease (COPD), or kidney failure.
What if? If a patient has severe diarrhea, they lose a large amount of bicarbonate. This depletes the body's primary buffer, leading to metabolic acidosis because there is not enough base to neutralize the normal metabolic acids.

How to Approach the Question

This is a factual recall question testing a fundamental concept in chemistry and physiology.
First, identify the core term in the question: 'buffer'.
Recall the definition of a buffer. Its primary function is to resist pH changes.
Evaluate the options based on this definition.
Option A (speed up) relates to catalysts. Option B (slow down) relates to inhibitors. Option D (change color) relates to indicators. Option C (maintain pH) directly matches the definition of a buffer.

Concept Tested & Keywords

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Practise the full NORCET 1 - 2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.