Acids and Bases
Indicators Substances that change colour in acids or bases can be used to tell if a substance is acidic, basic or neutral many are form natural sources (red cabbage, lichen (litmus paper), tea leaves, beets) synthetic ones turn different colours for different pH levels
pH means power of the [H]+ ion refers to the concentration of Hydrogen ions in a solution indicates the strength of acids and bases on a scale of 0 -14 pH of 7 is neutral (neither acid or base) each number represents a strength 10X more powerful (e.g. pH 10 is 10X more basic than pH 9, and pH 2 is 1000X more acidic than pH 5)
pH of Everyday
Properties of Acids Dissolve in water to form [H]+ ions Turn litmus paper red React with metals to form H2 gas Taste sour Feels like water but can burn your skin
Properties of Bases Dissolve in water to produce [OH]- ions turns litmus blue tastes bitter feels slippery to the touch (detergents)
Neutralization Reactions When a base and an acid react together to form a salt and water HCl + NaOH NaCl + H2O Acid + Base = Salt + Water (this example is table salt, but a "salt" is any compound made up of positive and negative ion pairs) The products of the reaction are neither acid or base - they are neutral Prediction activity…
Practice Try these Neutralization reactions + balance!!: H2SO + NaOH HCl + Ca(OH)2 HCl + Li(OH) H2CO3 + KOH