A buffer solution contains a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid. The important aspect of the buffer solution is that the pH of the solution is minimally changed when small amounts of acid or base are added or when the solution is slightly diluted. […]
Indicators may be considered as weak acids or weak bases that act like buffers and also exhibit color changes as their degree of dissociation varies with pH. For example, methyl red shows its full alkaline color, yellow, at a pH of about 6 and its full acid color, red, at about pH 4. Dissociation and […]
The three primary states of matter are solid, liquid, and gas. A fourth state of matter is the liquid crystalline state or mesophase. Liquid crystals (LCs) represent a unique state of matter existing between the ordered solid and disordered liquid states. Structure of Liquid Crystals The two main types of liquid crystals are termed smectic […]
Real gases behave like ideal gases in the limits of low pressures and high temperatures, but they deviate significantly at high pressures and low temperatures. The compressibility factor Z = PV/nRT is a convenient measure of the deviation from ideal gas behavior. If the ratio (Z = PV/nRT) is plotted against P at constant temperature, […]
An ideal gas is a fundamental theoretical model in chemistry and physics that simplifies the behavior of real gases. This hypothetical gas assumes molecules have negligible volume and experience no intermolecular forces, perfectly following kinetic theory principles. While no real gas is truly ideal, this model provides essential insights into pressure, volume, and temperature relationships […]
Matter makes up everything around us — from the air we breathe to the stars in the sky. But did you know it transforms between distinct states? In this guide, we’ll explore the fundamental states of matter (solid, liquid, and gas), their properties, real-world examples, and how they shape our universe. Perfect for students, educators, […]
Phosphate-buffered saline (PBS) is a buffer solution frequently used in pharmaceutical practice, particularly in the formulation of ophthalmic solutions. It is also used in colorimetric determination of pH and in research studies where maintaining a constant pH is essential. Phosphate-buffered saline (PBS) contains sodium chloride (NaCl) and dibasic sodium phosphate (Na2HPO4). It may also contain […]
What Is A Buffer Solution? Buffer solution is a combination of a weak acid and its conjugate base (i.e., its salt) or a weak base and its conjugate acid acts as a buffer. If 1 mL of a 0.1 N HCl solution is added to 100 mL of pure water, the pH is reduced from […]
The Henderson-Hasselbalch equation is used in situations where both undissociated acids and their conjugate bases are present in a solution. This situation can occur by adding the conjugate base to a solution of a weak acid or by partially neutralizing the weak acid with a strong base. Mixtures of an undissociated weak acid and its […]
When a weak acid is dissolved in water, the acid will undergo ionization. The ionization of a weak acid, HA, in water can be expressed as: $$ HA+H_2O⇄H^++A^- $$ Four species are present in the solution of the weak acid at equilibrium: HA, A−, H+, and OH−. To calculate the concentrations of the four species […]