Chemistry Acids and Alkalis Quiz

Acids and Alkalis

• Acids: Substances containing hydrogen, often liquids, that react with other substances to form salts. Some can burn or dissolve materials. Acids have a pH lower than 7 and taste sour. Examples include hydrochloric acid (in stomach), ethanoic acid (in vinegar), and citric acid (in lemons). Lab acids are corrosive.
• Alkalis: The chemical opposite of acids. They feel soapy and are bases. Examples include soap solutions and toothpaste. Lab alkalis are corrosive. Not all bases are alkalis.
• Corrosive: Substances that can burn or damage skin and eyes. Acids and alkalis can be corrosive.
• Concentrated: A high amount of solute (acid or alkali) dissolved in a solvent (usually water).
• Dilute: A low amount of solute dissolved in a solvent.
• Hazard Symbols: Warnings on chemicals indicating potential harm (e.g., corrosive, irritant).

Indicators and pH Scale

• Indicators: Substances that change color depending on whether a solution is acidic or alkaline. Red cabbage juice is a natural indicator.
• Litmus: A solution of dyes from lichens. Litmus paper (red and blue) responds to acids and alkalis (e.g., red litmus turns blue in alkalis, blue litmus remains blue in acids).
• Universal Indicator: A mixture of dyes that changes color to show the acidity or alkalinity of a solution.
• pH Scale: A scale measuring acidity or alkalinity. Pure water (neutral) is pH 7. Lower numbers indicate acidity, higher numbers indicate alkalinity.

Neutralization

• Neutralization: The chemical reaction between an acid and an alkali.
• Base: A substance that neutralizes an acid. Some bases dissolve in water (these are called alkalis).
• pH 7: Neutral pH.
• Uses of Neutralization: Dock leaves, quicklime/calcium oxide for soil, calcium hydroxide for factory waste, relief creams (for stings, acid/alkali treatment) and antacids for indigestion.

Making Salts

• Salt: A substance formed when an acid reacts with a metal or a metal-containing compound.
• Example: Copper sulfate crystals can be formed through such a reaction.

Test your knowledge on acids, alkalis, and their properties. This quiz covers definitions, examples, and the pH scale, providing insight into chemical reactions and safety. Perfect for students looking to reinforce their understanding of basic chemistry concepts.