chem qe

• An acid produces hydrogen ions in aqueous solution.
• Cu, Ag, and Pb do not react with acids.
• Acids only display their properties when dissolved in water.
• A base reacts with an acid to produce salt and water.
• All alkalis are bases but not all bases are alkali (bases are insoluble in water).
• Strength refers to how easily an acid/alkali ionizes when dissolved in water.
• A strong acid completely ionizes while a weak acid only partially ionizes.
• The strength of an acid is not affected by its concentration.
• The pH scale is a set of numbers from 0-14 that indicates whether a solution is acidic, alkaline, or neutral.
• Acidic solutions have higher concentration of hydrogen ions while alkaline solutions have higher concentration of hydroxide ions (neutral is =).
• We can measure pH using pH indicators, pH sensors, and meters.
• Universal indicator contains a mixture of dyes.
• pH level controls soil’s acidity.
• Most plants grow when the soil is neutral/slightly acidic (5-9).
• Calcium oxide (quicklime) and hydroxide (slaked lime) helps lime the soil.
• Most oxides of non-metals are acidic oxides and react with alkalis to form salt and water.
• Most oxides of metals are basic oxides and react with acids to form salt and water.
• Amphoteric oxides are metallic oxides that react with both acids and bases.
• Neutral oxides show neither basic or acidic properties.
• Oxidation takes place if a substance gains oxygen, loses hydrogen, loses electrons, or increases oxidation state.
• Reduction takes place if a substance loses oxygen, gains hydrogen, gains electrons, or decreases oxidation state.