Practice AND Review Answers 1. Identify as an acid or base or other and name: a. Ca(OH)2 base/calcium hydroxide h. H2CO3 carbonic acid b. H2SO4 sulfuric acid i. HNO3 nitric acid c. HNO2 nitrous acid j. H3PO4 phosphoric acid d. Mg(OH)2 base/magnesium hydroxide k. NaOH base/sodium hydroxide e. CH4 neither/methane l. H2SO3 sulfurous acid f. HI hydroiodic acid m. NH3 base/ ammonia g. CsOH base/ cesium hydroxide n. NaBr neithersalt/ sodium bromide 2. In an acid is the hydrogen ion concentration higher than or lower than the hydroxide ion concentration? Acid high H+ concentration, low OH- conc 3. Give me the hydrogen ion concentration range and pH range for acids and give me the hydroxide ion range and pOH range for bases. pH = 0-7 Acid pH Base = 7-14 [H+] = 1X 10-7 to 1X 100 [OH-] = 1X 10-14 to 1X 10-7 4. What is the pH of a solution that has a hydrogen ion concentration of 2.5x10-5M. What is the pOH of this solution? I think I messed up and had a positive exponentpH = 4.6 pOH = 9.4 5. If the pOH of a solution is 13.0, what is the HYDROGEN ion concentration? pH= 1 H+ conc =.1 6. The pH and pOH of a solution must add up to equal what? The hydrogen ion and hydroxide ion concentrations of a solution must add up to equal what? 7. If the hydroxide ion concentration of a solution is 2.65x10-2, what is the hydrogen ion concentration, pH, and pOH. Is this solution acidic of basic? 1.0X10-14 /2.65x10-2 = [H+] = 3.77x10-13 pOH=1.6 pH=12.4 8. Give the definitions of all three methods of defining acids and bases. (Arrhenius, Bronsted Lowry, and Lewis) Look them up 9. Is NH3 an Arrhenius base? Is it a Bronsted Lowry base? Explain your answers. Not Arrhenius base, No OH- present so can’t be Arrhenius, H+ion acceptor to become NH4+ 10. Identify the acid, base, conjugate acid, and conjugate base in the following reactions. a. HNO3 + H2O H3O+ + NO3b. CO32- + H2O HCO3- + OHAcid base CA CB Base Acid CA CB + + CH3COOH + H2O H3O + CH3COO d. H3PO4 + H2O H + H2PO4Acid base CA CB Acid base CA CB e. H2PO4- + H2O H+ + HPO4211. Name 4 strong acids and 4 strong bases. Acids-hydrochloric, sulfuric,lemon juice,phosphoric,stomach Bases- NaOH(lye), other hydroxides 12. What is the molarity of phosphoric acid if 50.0 mL of the solution is neutralized by 45.2 mL of 0.25 M NaOH? Predict products and balance. H3PO4 + 3NaOH Na3PO4 + 3H2O .25M = x/.0452liters NaOH x= .0113 moles NaOH divided by 3 for mole ratio .0038 mol acid/.050 liters = .076M H3PO4 13. How many moles of magnesium hydroxide are needed to completely neutralize 0.25 moles of nitric acid? Predict products and balance. Mg(OH)2 + 2HNO3 Mg(NO3)2 + 2H2O Mole ratio .25/2 = .125moles 14. How many mL of 3.0 M KOH are needed to prepare 870 mL if 0.20 M KOH? M1V1=M2V2 3.0M(V2) = .20M(870mL) V2=58mL 15. If you need 50.0 mL of 0.152 M HCl to neutralize 29.2 mL of Ca(OH)2, what is the molarity of the base? 2HCl + Ca(OH)2 2 H2O + CaCl2 0.152M HCl = x moles/.050 liters x= .0076 molesAcid .0038 moles of base/ .0292liters = .13 Molar Ca(OH)2 .26 16. What is the molarity of a solution of base if 25.0 mL is neutralized by 75.0 mL of 0.40 m acid? M1V1=M2V2 17. Define titration. Look it up 18. How many moles of potassium hydroxide are needed to completely neutralize 1.56 moles of phosphoric acid? Predict products and balance. 3KOH + H3PO4 K3PO4 + 3H2O 4.68 moles 19. How many moles of calcium hydroxide are needed to neutralize 6.30 moles of nitric acid? Predict products and balance. Ca(OH)2 + 2HNO3 Ca(NO3)2 + 2H2O 2:1 ratio 6.3 /2 = 3.15 moles 20. How many milliliters of 2.50M HCl must be added to 25.0 mL of 1.00M potassium hydroxide to make a neutral solution? Predict products and balance. HCl + KOH KCl + H2O 1M = x/.025liters x = .025 moles KOH 2.50 M = .025 mole HCl/ x liters .01 liters = 10 milliliters 21. If the [H+] of a solution is 2.3X10-3, what is the pOH of this solution? -log ( 2.3X10-3) = pH= 2.6 pOH= 11.4 22. What is always the product of an acid/base neutralization? Water and salt