82 articles
Acids, Bases & Salts
pH, strong and weak acids, buffers, titrations, indicators and salt chemistry.
Acid–Base Indicators: How They Change Colour
What indicators are, why they change colour with pH, the chemistry of the colour switch, natural and synthetic examples, and how indicators are used in the lab, the garden and medicine.
Handling Acids and Bases Safely in the Lab
A practical safety guide for acids and alkalis: hazard labels, protective equipment, diluting correctly, safe storage and transport, what to do after spills and splashes, and the specific hazards of common reagents.
Acidic Foods, Tooth Enamel and pH
How acids from food, drinks and mouth bacteria dissolve tooth enamel, the critical pH of 5.5, why fluoride helps, how saliva repairs teeth, and practical chemistry-based ways to protect them.
Acids and Bases: Myths and Misconceptions
Twelve common misconceptions about acids, bases and pH, from 'all acids burn' to 'neutralisation always gives pH 7', each with a clear explanation of what's actually true and why.
Acids vs Bases: The Key Differences
A side-by-side comparison of acids and bases: definitions, ions, pH, indicator colours, reactions, strength, examples and safety, plus how they cancel each other out.
Alkaline Water: What the Chemistry Says
Alkaline water is sold with big health claims. We look at what it is, how it's made, what happens when you drink it, what the body does with pH, and what the evidence does and doesn't support.
Arrhenius Acids and Bases
The Arrhenius definition explained: acids make H⁺, bases make OH⁻ in water. How Svante Arrhenius arrived at it, how to apply it, worked examples, and where the theory breaks down.
Bases vs Alkalis: Are They the Same?
Every alkali is a base, but not every base is an alkali. Learn the exact difference, which metal hydroxides dissolve, how to test for each, and the exam answers that earn marks.
How to Calculate pH from Concentration
Step-by-step pH calculations: strong acids, strong bases, converting pH back to [H⁺], dilutions, mixing an acid with a base, and the very dilute acid trap, with worked answers.
Concentrated vs Strong: Two Words Students Mix Up
Strength is about how completely an acid ionises; concentration is about how much is dissolved. Clear definitions, a four-way comparison, pH examples and exam-ready wording.
Acids and Bases in Your Home
A room-by-room tour of the acids and bases in an ordinary home: kitchen, bathroom, laundry, garden and medicine cabinet, with their chemical names, approximate pH, what they do and how to use them safely.
Litmus Paper: How It Works
What litmus is made from, why it turns red in acid and blue in alkali, red vs blue vs neutral litmus paper, how to use it correctly, its limits, and the history of one of chemistry's oldest indicators.
Naming Salts from Their Parent Acids
How to name any salt: the metal comes first, the acid decides the ending. Chlorides, sulfates, nitrates, carbonates, phosphates, ethanoates, hydrogen salts and transition metal Roman numerals, with practice.
Sørensen and the Invention of the pH Scale
How a Danish chemist at a beer laboratory invented pH in 1909, why brewing needed it, what the 'p' stands for, and how pH moved from hydrogen ion concentration to activity and today's electrode measurements.
Make a Red Cabbage pH Indicator
A safe, low-cost practical: extract anthocyanin indicator from red cabbage, test household substances, build your own pH colour scale, and understand the chemistry behind the colours.
What Is a Salt in Chemistry?
Salt means far more than table salt. The chemical definition, how salts form, their structure and properties, soluble vs insoluble salts, hydrated salts and the salts you meet every day.
Stomach Acid: How Strong Is It Really?
The real chemistry of gastric acid: how the stomach makes hydrochloric acid, its concentration and pH, why it doesn't digest the stomach, what heartburn is, and how antacids and acid-reducing medicines work.
The Strong Acids (and Why There Are So Few)
The complete list of common strong acids, their formulas, estimated pKa values and uses, why hydrofluoric acid isn't on it, and how water levels them all to the same strength.
The Strong Bases: A Complete Guide
Which bases count as strong, why the Group 1 and heavier Group 2 hydroxides fully dissociate, the solubility catch with calcium hydroxide, superbases, and safe handling.
Teaching Acids and Bases: Practical Ideas
A teacher's guide to acids and bases: a lesson sequence, practicals and demonstrations that work, the misconceptions to expect, questioning strategies and differentiated activities for mixed-ability classes.
Universal Indicator and the pH Colour Chart
How universal indicator shows the whole pH scale in one set of colours, what's in it, how to read the colour chart, how accurate it is, and when to use paper, solution or a pH meter instead.
What Is a Base? Alkalis, Hydroxides and Everyday Examples
Bases explained from scratch: how they accept protons, why hydroxide ions matter, the difference between bases and alkalis, their properties, and where you find them at home.
What Is an Acid? Definitions, Properties and Examples
A clear introduction to acids: what makes a substance acidic, the H⁺ ion, how acids behave, the three definitions chemists use, and the acids you meet every day.
The pH Scale Explained: What pH Really Measures
What pH actually measures, why the scale is logarithmic, how pH and pOH relate, how to calculate pH, and the pH of everyday substances from lemon juice to bleach.
Acid–Base Reactions Practice Questions
25 practice questions on acid–base reactions: predicting products, balancing neutralisation equations, ionic equations, identifying acids and bases, and reacting quantities, with full worked answers.
Acid–Base Titration: Method, Equipment and Accuracy
A complete practical guide to acid–base titration: equipment, step-by-step method, concordant results, a fully worked calculation, sources of error and how to make your results more accurate.
Acidic Oxides vs Basic Oxides
Why metal oxides are basic and non-metal oxides are acidic, the amphoteric and neutral exceptions, their reactions with water, acids and alkalis, the Period 3 trend, and where these oxides matter in the real world.
Acids and Bases Study Guide
A complete revision guide to acids and bases: definitions, pH, strong vs weak, neutralisation, salts, titrations, Ka and buffers, with a checklist, key equations and exam tips for every level.
The Most Important Industrial Acids
The acids that underpin modern industry: sulfuric, phosphoric, nitric, hydrochloric, hydrofluoric, acetic and others, with how each is made, how much is produced, and what it's used for.
Amphoteric and Amphiprotic Substances
What it means for a substance to behave as both an acid and a base, the difference between amphoteric and amphiprotic, and the chemistry of water, aluminium oxide, zinc hydroxide and amino acids.