More on Acids and Bases

Acids Acids are compounds that increase the concentration of hydrogen ions [H+] when they dissolve in water. Acids solution have: pH below 7 Taste sour Turn litmus paper red.

Bases Bases are compounds that increase the concentration of hydroxide ions [OH-] when they dissolve in water. Bases have: pH greater than 7 Taste bitter Feel slippery Turn litmus paper blue

pH pH (0-14) measures the hydrogen ion concentration in water. Each pH unit involves a tenfold change in hydrogen ion concentration. The pH number and the [H+] are inversely related because pH = - log [H+]

pH continued An increase of 1 pH unit means that the hydrogen ion concentration has decreased 10 times. A decrease of 1 pH unit means that the hydrogen ion concentration has increased 10 times.

Arrhenius Arrhenius acids form hydrogen ions in aqueous solutions Arrhenius bases form hydroxide ions in aqueous solutions.

Bronsted-Lowry Acids are proton donors Bases are proton acceptors

Lewis Lewis Acids can accept a pair of electrons Lewis Bases can donate a pair of electrons

Strong Acids & Bases Both strong acids and bases dissociate completely in water, and therefore are strong electrolytes. In a solution of a strong acid like hydrochloric acid, almost all of the HCl molecules dissociate: HCl  H+ + Cl- When 1 mole of HCl dissociates, it produces 2 moles of ions.

Weak Acids and Bases Weak acids and bases are weak electrolytes and only partially dissociate.. In a solution of a weak acid like acetic acid, only a few of the CH3COOH molecules dissociate CH3COOH  H+ + CH3COO- When 1 mole of CH3COOH dissociates it produces LESS than 2 moles of ions because only some of the molecules dissociate.

pH of weak Acids and Bases A 1 M solution of HCl would have a LOWER pH than a 1M solution of CH3COOH because HCl produces more moles of H+ with its greater degree of dissociation.

Acid Base Pop Quiz If the pH is 4 what is the pNeutral? If the concentration of water is 30M, then what is the ABC? If the indicator was Hydronium, what happened in the titration

This quiz was a JOKE!!! Next time, BE PREPARED FOR CLASS!!!