Buffers in pharmaceutical systems play a crucial role in maintaining the stability, efficacy, and safety of pharmaceutical products by controlling pH levels. Importance of Buffers in Pharmaceutical Systems 1) pH Control: Buffers maintain consistent pH levels, affecting drug stability, solubility, and absorption. 2) Stability: Many drugs degrade or precipitate with pH fluctuations. Buffers prevent this … Read more
A buffer solution resists significant changes in pH when small amounts of acid or base are added or when diluted. Buffers are crucial in biological systems, industrial processes, and analytical chemistry. Types of Buffer Solutions: Acidic Buffer: Contains a weak acid and its conjugate base (e.g., acetic acid and sodium acetate). The weak acid neutralizes … Read more
Acid and Base theory contains 3 main concepts that is Arrhenius, Bronsted-Lowry & Lewis concept, these are listed below Arrhenius Concept: Acids: Substances that dissociate in water to produce hydrogen ions (H⁺). Bases: Substances that dissociate in water to produce hydroxide ions (OH⁻). Example: Acid: HCl(aq) → H⁺(aq) + Cl⁻(aq) Base: NaOH(aq) → Na⁺(aq) + … Read more
Acids, bases and buffers are essential concepts in chemistry and play critical roles in various biological and industrial processes. Acids: Acids are substances that donate hydrogen ions (H⁺) or protons when dissolved in water. They typically have a sour taste and can be corrosive to metals. Acids can be classified into two main categories: Strong … Read more
The modified limit test for sulfate is based on gravimetric analysis, where sulfate ions (SO₄²⁻) are precipitated as barium sulfate (BaSO₄) using barium chloride (BaCl₂). The precipitate is then collected, dried, and weighed to determine the sulfate concentration. Chemical Reaction: Ba2+(aq) + SO₄2−(aq) → BaSO₄(s) Procedure for Limit Test for Sulfate: Prepare Test Solution: Prepare … Read more
The modified limit test for chloride is based on the Volhard titration method, where chloride ions (Cl⁻) are precipitated with silver nitrate (AgNO₃) and the excess silver nitrate is titrated with ammonium thiocyanate (NH₄SCN). The process involves two key reactions: Chemical Reactions of Limit Test for Chloride: Precipitation of Chloride Ions: Ag + (aq) + … Read more
The limit test for heavy metals is a qualitative test that determines if the concentration of heavy metal ions (e.g., Pb²⁺, Cu²⁺, Cd²⁺) in a sample is below a predefined acceptable limit. The test is based on the reaction between heavy metal ions and sulfide ions (S²⁻) from sodium sulfide (Na₂S), forming colored metal sulfide … Read more
The limit test for lead is a qualitative test that determines whether the concentration of lead ions (Pb²⁺) in a sample is below a predefined limit. It is based on the colorimetric reaction between lead ions (Pb²⁺) and potassium chromate (K₂CrO₄), which forms a yellow-colored precipitate of lead chromate (PbCrO₄). Chemical Reaction: Pb2 + (aq) … Read more
The limit test for arsenic is a qualitative test used to determine if the concentration of arsenic in a sample is below a predefined limit. The test is based on the reduction of arsenic (As) to arsine gas (AsH₃), which reacts with silver nitrate to form a yellow to brown stain on filter paper. Chemical … Read more
The limit test for iron is a qualitative test that checks whether the iron ion (Fe³⁺) concentration in a sample is below a specified limit. It is based on a colorimetric reaction between iron ions (Fe³⁺) and potassium thiocyanate (KSCN), forming a red-colored complex. Chemical Reaction: Fe3+(aq) + 6SCN−(aq) → [Fe(SCN)6]3−(aq) Procedure of Limit test … Read more
