Aim: What happens when you add an acid to a base? Objectives: 1.Students should know the products of a reaction between H + and OH - (H 3 O + and OH - ). 2.Students should know the general products of a neutralization reaction. 3.Students should be able to determine the specific products of a reaction between a given acid and a base.

Adding an Acid to a Base What ion is the defining ion of an acid? What ion is the defining ion of a base? What is the product of adding these ions together? H + + OH -  H 3 O + + OH -  Why do you think the type of reaction of combining an acid and a base is called a neutralization reaction?

Acid/Base Reactions What are the products when these ions are part of an acid and a base? HCl + NaOH  Ca(OH) 2 + H 2 SO 4  HNO 3 + KOH 

Aim: How do we figure out the concentration of an acid or base if it is unknown? 1. Students should know the definition of titration. 2.Students should know why and how the process of titration is done. 3.Students should be able to determine concentration or volume of an acid or base using the formula M A V A = M B V B 4.Students should be able to determine the effect of diprotic acids or dihydroxy bases on a neutralization reaction. 5.Students should know how the strength of an acid is determined.

Titration Indicator

Titration What is it? Adding an acid or base of known concentration to an acid or base of unknown concentration until it neutralizes it. Why do it? The purpose is to determine the concentration of the unknown. M A x V A = M B x V B Table T You will be given 3 variables and will have to solve for the 4 th.

Steps in Titration [Example] 1.Add 20 ml of vinegar (acetic acid) to flask. 2.Add phenolphthalein. What color should it turn? 3.Read the burette containing NaOH to obtain the initial volume. Slowly add NaOH from the buret to the acid in the flask until the mixture turns a light pink. Record the final volume reading on the burette. Volume of base added: V final ____ - V initial _____= _______. 4.Given: M B = 1.0 M V A = 20 ml From Titration:V B = ______ Unknown = M A 5. Plug in and solve: M A V A = M B V B I have an acid of unknown concentration. I’d like to know what the conc. is.

Titration Problems If it takes 54 ml of 0.1 M NaOH to neutralize 125 ml of HCl solution, what is the concentration of the HCl? If it takes 25 ml of 0.05 M HCl to neutralize 345 ml of NaOH solution, what is the concentration of NaOH? If it takes 50 ml of 0.5 M KOH to neutralize 125 ml of H 2 SO 4, what is the concentration of the H 2 SO 4 ?

Regents Questions

Does the formula of the acid or base affect neutralization? What ions are involved in neutralization? How might the neutralization between HCl and NaOH differ from the neutralization between HCl and Ca(OH) 2 ? Monoprotic Acid: HCl 1.0 M HCl has 1.0 mole of H + ions. Monohydroxy Base: NaOH 1.0 M NaOH has 1 mole of OH - ions. Diprotic and Dihydroxy? Triprotic?

Solve the following: How many mL of 1.0 M H 2 SO 4 are required to completely neutralize 30 mL of 1.0 M Ca(OH) 2 ? How many mL of 1.0 M H 2 SO 4 are required to completely neutralize 30 mL of 1.0 M NaOH? How many mL of 0.2 M H 3 PO 4 are required to completely neutralize 10 mL of 0.1 M Mg(OH) 2 ?

What makes an acid or base ‘strong’ or ‘weak’? The strength of an acid or base is determined by the concentration of H + ions or OH - they release in solution. HCl is a strong acid because when dissolved in water, every HCl dissociates into H + and Cl -. Ex: 100HCl  100 H + and 100 Cl - Nitrous acid is a weak acid because when dissolved in water, not every HNO 2 dissociates. Ex: 100HNO 2  25 H NO HNO 2 NOTE: This concept is different from comparing concentrations of H + ions in monoprotic and diprotic acids.

Strong Acids Strong Bases s/5anions/acidbaset.htm

Aim: What types of reactions occur with acids and bases? Objectives: Students should be able to identify neutralization reactions and recognize that they are double replacement reactions. Students should recognize reactions involving metals and acids as single replacement reactions. Students should be able to determine which metals will react with acids

Acid-Base Reactions Double Replacement: Neutralization Acid + Base  Water + Salt –HCl + NaOH  H 2 O + NaCl –H 2 SO 4 + Ca(OH) 2  2H 2 O + CaSO 4 –HNO 3 + Mg(OH) 2  2H 2 O + Mg(NO 3 ) 2 Single Replacement: Metal + Acid Metal + Acid  H 2 (g) + Salt –Zn + 2HCl  H 2 + ZnCl 2 –Mg + H 2 SO 4  H 2 + MgSO 4 –Cu + HCl  NO REACTION (Cu is below H 2 on Table J) Which other metals will NOT react with acids to form H 2 gas?

Single Replacement Review Use Table J to determine if single replacement reactions can occur. –An element can only replace something that is less reactive than itself. On Table J elements are listed in order of most reactive to least reactive. This reaction will occur: Cr + CoCl 2  Co + CrCl 2 Cr can replace the Co in the compound because Cr is higher than Co on Table J (more active). This reaction will NOT occur: Co + CrCl 2  NO REACTION Co is lower on Table J than Cr (less active) so it cannot come in and replace Cr in the compound. This rule also applies to the right side of the table where nonmetals can replace nonmetals. Cl can replace Br, but Br cannot replace Cl.

Double Replacement Review Double replacement reactions occur if you create a new compound. In a neutralization double replacement reaction, the new compound that is produced is H 2 O. HCl + NaOH  H 2 O + NaCl In a double replacement reaction involving soluble salts, the new product that is formed is insoluble. If no insoluble product is formed, the double replacement reaction did NOT occur. –NaCl + NH 4 ClO 3  NO REACTION because the potential products (NaClO 3 and NH 4 Cl) are both soluble. –Li 2 SO 4 + Ca(OH) 2  2LiOH + CaSO 4 (s) [CaSO 4 is insoluble so this reaction will occur.]