These free B.Pharm notes on major extracellular and intracellular electrolytes cover chapter 8 of Pharmaceutical Inorganic and Analytical Chemistry (BP106T), a first-semester subject. Read the key points below, then study the complete chapter PDF. You can browse every chapter in the Pharmaceutical Inorganic and Analytical Chemistry category.
Table of Contents
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Overview of major extracellular and intracellular electrolytes
These notes explain body fluid compartments, electrolytes and their functions, then cover the major physiological ions: sodium, chloride, potassium, calcium, magnesium, phosphate and bicarbonate. They go on to replacement and combination therapy, the monographs of sodium chloride, potassium chloride and calcium chloride with their assays, oral rehydration salt, and acid-base imbalance and physiological acid-base balance.
Key points on major extracellular and intracellular electrolytes
- Sodium and chloride are the main ions outside the cells, while potassium and phosphate are the main ions inside the cells.
- Normal plasma sodium is 136 to 142 mEq/litre, and sodium makes up about 90% of extracellular cations.
- Sodium chloride and potassium chloride are assayed by Mohr’s method, titrating with 0.1 N silver nitrate using potassium chromate as indicator.
- Calcium chloride is assayed by complexometric titration with 0.05 M disodium edetate, the colour changing from red-purple to deep blue.
- Normal blood pH is 7.35 to 7.45; below 7.35 the condition is acidosis and above 7.45 it is alkalosis.
Relevance to pharmacy practice
Pharmacists supply electrolyte replenishers such as normal saline, potassium chloride, calcium chloride injection and ORS to patients who lose fluid through vomiting, diarrhoea, burns or fever. Knowing normal ion levels, imbalance symptoms and the official assays helps students check the quality of these products and use them safely.
Every chapter in this subject builds on the one before it, so do not skip topics that look simple. Definitions, principles, procedures and examples are the parts that examiners return to most often, and a clear understanding here will also make later subjects easier to follow in the coming semesters.
Frequently asked questions on major extracellular and intracellular electrolytes
What is normal saline?
Normal saline is a 0.9% solution of sodium chloride in water. It has the same osmotic pressure as body fluids, so it is isotonic and is given intravenously when fluid and electrolytes are lost.
What is the composition of the WHO/UNICEF ORS formula?
Per litre it contains 13.5 g glucose, 2.6 g sodium chloride, 2.9 g trisodium citrate dihydrate and 1.5 g potassium chloride, made up to 1 litre with drinking water.
What are the uses of calcium chloride injection?
Calcium Chloride Injection USP is used in hypocalcemia, magnesium intoxication, hyperkalemia and cardiac resuscitation. It is given only by slow intravenous injection, not intramuscularly or subcutaneously.
Quick revision checklist
Use this self-test after reading the chapter on major extracellular and intracellular electrolytes. If you can do all of the following without looking at your notes, you are ready for the exam.
- I can explain: the three body fluid compartments
- I can explain: normal plasma levels of the major ions
- I can explain: hyponatremia, hypokalemia and their causes
- I can explain: the Mohr’s method assay of sodium chloride
- I can explain: metabolic acidosis versus metabolic alkalosis
Study and exam tips
Start by reading the chapter once for the overall idea, then revise major extracellular and intracellular electrolytes using headings, definitions, principles, reactions and examples. Short-answer questions in the university exam usually ask for definitions, principles, procedures, reactions and uses, so write these in your own words and practise the equations, tables and flow charts that the chapter has.
For wider reading, standard books and open resources such as the NCBI Bookshelf help you confirm terms and see more examples. Revise major extracellular and intracellular electrolytes again a day later and again a week later, because spaced revision improves long-term memory.
This page is part of the Pharmaceutical Inorganic and Analytical Chemistry series for first-semester B.Pharm students on B.Pharm Guru, where every chapter has a short summary and a full PDF. Bookmark this page and share it with classmates who are preparing for the same exam.
Related notes: 10. NON-AQUEOUS TITRATIONS, 11. PRECIPITATION TITRATIONS AND GRAVIMETRY.
Next: 9. ACID-BASE TITRATIONS. Back to the Pharmaceutical Inorganic and Analytical Chemistry category.
