Reviewed 6 October 2026 · 4 min read
Test Guruji editorial · original lesson
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Read the scale correctly
For ordinary aqueous solutions at about 25°C, pH below 7 is acidic, 7 is neutral and above 7 is basic. An indicator changes colour in response to chemical conditions. Blue litmus turns red in an acidic solution; red litmus turns blue in a basic one.
Acid reacting with a metal carbonate releases carbon dioxide along with salt and water. Neutralisation between an acid and a base commonly produces salt and water. Do not assume every salt solution is neutral: its parent acid and base affect its behaviour.
Revise through predictions
Predict the gas or indicator change before looking at the answer. Keep concentration and acid strength separate: a concentrated solution and a strong acid describe different properties. Use the textbook explanation whenever a question asks for mechanism rather than a familiar example.
Sources and editorial context
Last editorial check: 6 October 2026. Verify changing facts and your exam’s requirements from current official notices. Practice questions are editorial originals.
Original revision quiz
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