3. Question: Write the chemical reaction when lithium hydroxide is mixed with carbonic acid. Step 1: write out the reactants LiOH (aq) + H 2 CO 3 (aq)  Step 2: determine products … H 2 O and Li 2 (CO 3 ) LiOH (aq) + H 2 CO 3 (aq)  Li 2 CO 3 (aq) + H 2 O (l) Step 3: balance the equation 2LiOH (aq) + H 2 CO 3 (aq)  Li 2 CO 3 (aq) + 2H 2 O (l) lithium hydroxide + carbonic acid  lithium carbonate + water Writing neutralization equations When acids and bases are mixed, a salt forms NaOH + HCl  H 2 O + NaCl base + acid  water + salt Ca(OH) 2 + H 2 SO 4  2H 2 O + CaSO 4

4. a)iron(II) hydroxide + phosphoric acid b)Ba(OH) 2 (aq) + HCl(aq) c)calcium hydroxide + nitric acid d)Al(OH) 3 (aq) + H 2 SO 4 (aq) e)ammonium hydroxide + hydrosulfuric acid f)KOH(aq) + HClO 2 (aq) Assignment Write balanced chemical equations for these neutralization reactions. Under each compound give the correct IUPAC name.

5. a) 3Fe(OH) 2 (aq) + 2H 3 PO 4 (aq)  Fe 3 (PO 4 ) 2 (aq) + 6H 2 O(l) iron(II) hydroxide + phosphoric acid  iron (II) phosphate b) Ba(OH) 2 (aq) + 2HCl(aq)  BaCl 2 (aq) + 2H 2 O(l) barium hydroxide + hydrochloric acid  barium chloride c) Ca(OH) 2 (aq) + 2HNO 3 (aq)  Ca(NO 3 ) 2 (aq) + 2H 2 O(l) calcium hydroxide + nitric acid  calcium nitrate d) 2Al(OH) 3 (aq) + 3H 2 SO 4 (aq)  Al 2 (SO 4 ) 3 (aq) + 6H 2 O(l) aluminum hydroxide + sulfuric acid  aluminum sulfate e) 2NH 4 OH(aq) + H 2 S(aq)  (NH 4 ) 2 S(aq) + 2H 2 O(l) ammonium hydroxide+ hydrosulfuric acid  ammonium sulfide f) KOH(aq) + HClO 2 (aq)  KClO 2 (aq) + H 2 O(l) potassium hydroxide + chlorous acid  potassium chlorite

6. Calculations involving Neutralization Reactions

7. Sample Problem 1 What volume of 0.250M sulfuric acid, H 2 SO 4 (aq) is needed to react completely with 37.2 mL of 0.650 M potassium hydroxide, KOH (aq)? 1.Step 1. Write a balanced equation for the reaction. H 2 SO 4 (aq) + 2KOH (aq)  2H 2 0 (l) + K 2 SO 4 (aq)

8. Step 2. Using the information provided, calculate the number of moles of base. c =.650 mol/L V= 37.2 mL = 0.0372 L n = cV = (.65 mol/L)(0.0372L) = 0.02418 mol H 2 SO 4 (aq) + 2KOH(aq)  2H 2 0(l) + K 2 SO 4 (aq)

9. Step 3. Determine the number of moles of H 2 SO 4 needed to neutralize the lithium hydroxide. (Use mole ratio, if necessary) =0.02418mol KOH X 1 mol H 2 SO 4 2 mol KOH =0.01209 mol H 2 SO 4

10. Step 4. Find the volume of H 2 SO 4 (aq) based on the moles and concentration of H 2 SO 4 solution. c= n/V V= n/c = 0.01209 mol/0.250M = 0.0484 L = 48.4 mL H 2 SO 4 (aq) + 2KOH(aq)  2H 2 0(l) + K 2 SO 4 (aq)

11. Problem 2: A 25.0 mL sample of hydrochloric acid is titrated with 1.00 mol/L NaOH. The end point is reached when 67.5 mL of base has been added. Calculate the concentration of the acid in mol/L. 1.Step 1. Write a balanced equation for the reaction. HCl(aq) + NaOH(aq)  H 2 0(l) + NaCl(aq)

12. Step 2. Using the information provided, calculate the number of moles of base. c = 1.00 mol/L V= 67.5 mL = 0.0675 L n = cV = (1.00 mol/L)(0.0675L) = 0.0675 mol

13. HCl(aq) + NaOH(aq)  H 2 0(l) + NaCl(aq) Step 3. Determine the number of moles of HCl needed to neutralize the sodium hydroxide. (Use mole ratio, if necessary) In this case n A = n B = 0.0675 mol

14. HCl(aq) + NaOH(aq)  H 2 0(l) + NaCl(aq) Step 4. Find the concentration of HCl(aq) based on the moles and volume of HCl solution. c= n/V = 0.0675 mol/0.0250L = 2.70 mol/L

15. Calculate the % of HCl (as m/m) in the solution, given that its density is 1.100 g/mL 2.70 mol HCl 1.00 L of solution m=nM =(2.70 mol)(36.36g/mol) = 98.4 g m=DV =(1.100g/mL)(1000mL) = 1100 g % = 98.4g x 100 1100g = 8.95%

16. Titration Titrations are a chemical procedure involving the addition of a solution of known concentration. The objective is to determine the point in the reaction when the moles of the known solution is equal to the moles of the unknown solution. The concentration of the unknown solution can be determined by: Concentration unknown =Volume known x Concentration known Volume un known

17. Titration Terminology Titrant-solution of known concentration. It is added slowly using a burette Sample-solution of unknown concentration. It is contained in a flask Primary Standards/Solutions- Solution of know accurate concentrations that are used as titrants.

18. Titration Terminology Indicator-A solution that changes color at the equivalence point. Equivalence Point (Stoichiometric Point)-the amount of titrant required for a complete reaction to occur. (chemically equivalent amounts have reacted). Endpoint-The point in a titration where a measurable change occurs (indicator change, pH change)