2 Key Words Compare and contrast acid and base properties. Identify a substance as an acid or baseIdentify acids and bases based on an indicatorIdentify acids and bases based on their pHKey WordsAcidBaseIndicatorCorrosive
3 ACID BASE Sour (lemons) Bitter (soap) DO NOT taste. Corrosive (burn) Destroy bases(neutralization)Conduct electricityReact with most metals(hydrogen gas is made)Bitter (soap) DO NOT taste.Corrosive (burn)Destroy Acids(neutralization)Conduct electricityFeel slippery(destroy proteins & fats)
4 Acidic Basic (alkaline) H Cl H NO3 H 2SO4 H Br Na OH Ca( )2 OH K OH NH 3
5 H NO3 Ca( )2 OH Most acids and bases are aqueous when used. Most acids and bases are ionic compounds and include polyatomic ions.Acids tend to have “H” in their formula.Bases often have polyatomic “OH” (hydroxide) - Usually bonded to a 1A or 2A metal.HNO3Ca( )2OH
7 HNO3 (s) (aq) + NO3- (aq) H+ H2CO3 (s) 2 (aq) + CO3-2 (aq) H+ When dissolved in water, acids and bases dissociate into two ions.split apart into ionsThe hydrogen ion is responsible for the acid properties.HNO3 (s) (aq) + NO3- (aq)H+H2CO3 (s) (aq) + CO3-2 (aq)H+
8 Ca(OH)2 (s) Ca+2 (aq) + 2 (aq) OH- The hydroxide ion is responsible for the base properties.Ca(OH)2 (s) Ca+2 (aq) (aq)OH-KOH(s) K+ (aq) (aq)OH-
11 A substance that changes colour when added to an acid or base is called an indicator. There are many different types of indicators available.We often use paper containing the litmus dye as an indicator (red or blue litmus paper).
13 Most acids contain hydrogen. Most bases contain hydroxide (OH-)Acids dissociate in water to make hydrogen ions.Bases dissociate in water to make hydroxide ions.Indicators are substances that change colour to show the presence of an acid or base.