1. Acids and Bases Chapter 23

2. Common Acids and NameFormulaStrong/WeakWhere is it found? Hydrochloric acidHClStrongThe stomach, in the lab. Sulphuric acidH 2 SO 4 StrongAcid rain, car batteries, the lab. Nitric acidHNO 3 StrongAcid rain, in the lab. Ethanoic (acetic) acid CH 3 COOHWeakVinegar Methanoic (formic) acid HCOOHWeakAnt & nettle stings, descalers Citric AcidC6H8O7C6H8O7 WeakCitrus fruits

3. Acids Acids are H+ or proton donors: Properties Acids taste sour (e.g. vinegar, lemon juice). Acids are harmful to living cells. Aqueous solutions of all acids contain hydrogen ions, H+.

4. Water is needed

5. Common Bases NameFormulaWhere is it found? Sodium hydroxide (caustic soda)NaOHOven cleaners, in the lab. Calcium hydroxideCa(OH) 2 Soil lime, limewater Magnesium oxide (magnesia)MgOIndigestion tablets Calcium carbonateCaCO 3 Limestone, soil lime Sodium hydrogencarbonate (bicarbonate) NaHCO 3 Baking powder AmmoniaNH 3 Cleaning fluids, in the lab.

6. Base properties Most bases are oxides, hydroxides or carbonates of metals Soluble bases are known as alkalis. Aqueous solutions of alkalis contain hydroxide ions, OH-. Bases taste bitter.. Bases feel slippery

7. Base and indicators Bases turn red litmus blue. A common indicator, used to detect the presence of a base, is phenolphthalein which, when mixed with a base, turns pink. Bases release hydroxide ions in water solutions. NaOH (s) + H2O (l) à Na1+ (aq) + OH1- (aq) NH4OH (aq) ß -> NH41+ (aq) + OH1- (aq)

8. pH scale Water is defined as having a pH value of 7- neutral. Acidic solutions have pH values below 7. Alkaline (basic) solutions have pH values above 7. pH is a measure of the number of hydronium or hydroxide ions Logrithimic scale

9. pH scale

10. Reactions of Acids With metals Metals above copper in the reactivity series will react with acids, giving off hydrogen gas. The metal dissolves, forming a salt. METAL + ACID  SALT + HYDROGEN ex. Mg(s) + H2SO4(aq)  MgSO4(aq) + H2(g) This is why acids corrode metals, and must be stored in glass containers.

11. Base reactions With bases (metal oxides and hydroxides) The base dissolves in the acid and neutralises it. A salt is formed. ACID + BASE  SALT + WATER ex. H2SO4(aq) + CuO(s)  CuSO4(aq) + H2O(l) With metal carbonates Metal + Base  Salt + water + CO2 2HCl(aq) + CaCO3(s)  CaCl2(s) + H2O(l) + CO2(g)

12. Indicators Indicators- an organic compound that turns color in the presence of an acid or base

13. Naming Acids –Prefix is always hydro –Name the second element with the suffix - ic –HCl – hydrochloric –HF- Hydrofluoric

14. For the acid containing the most common polyatomic ion of its group simply use the first part of the polyatomic name and follow with the suffix ic. For the acid containing the polyatomic with one less oxygen than the ic, use the suffix ous. For the acid containing the polyatomic with two less oxygens than the ic, use the prefix hypo and the suffix ous. For an acid containing the polyatomic with one more oxygen than the ic, use the prefix per and the suffix ic.

15. Naming Bases and Salts Follow regular naming rules

16. Acid Reactions ACID+BASE  SALT+WATER Hydrochlor ic Acid + Sodium Hydroxide  Sodium Chloride +Water HCl+NaOH  NaCl+H2OH2O

17. ACID+METAL  SALT+ HYDROGEN GAS Hydrochloric Acid +Magnesium  Magnesium Chloride +Hydrogen HCl+Mg  MgCl 2 +H2H2

18. ACID+CARBONATESALT+WATER+ CARBO N DIOXID E GAS Hydrochloric Acid + Calcium Carbonate Calcium Chloride +Water+ Carbon Dioxide

19. Molarity Molarity indicates the concentration Given in the unit Moles/Liters Moles is the SI unit for quantity- it indicates 6.022 x10 22 atoms or molecules of a substance It is equal to the atomic weight of the element in grams Ex. 16.00 g of O is one mole 32.00 g of O 2 one mole

20. Neutralization Reactions in which an acid is added to a base cause neutralization This usually results in a salt and water IN the case of carbonate bases it results in a carbonate salt, water, and carbon dioxide

21. Titration A titration is a process where by the concentration of an unknown acid or base is determined by using a solution with a known concentration. This solution is known as the standard solution. The formula M1V1=M2V2 is used to determine the molarity of the unknown