Chemistry 102 Acids and Bases Exercise Roger Rowlett Spring 2008 This exercise consists of acid/base problems in order of increasing difficulty It is designed to test your understanding of acid/base concepts, and hopefully help identify areas in which your understanding is incomplete Strong and Weak Electrolytes Write out the major species present in an aqueous solution of the following compounds: • NaClO4, HCN, NaF, HBr, NH4NO3, CH3CH2NH2, HNO2 Recognizing acids and bases Classify the major species present in solution in question as strong/weak/pathetic acids/bases Acid-base equilibria Based on your answer to question 2, classify the aqueous solutions in question as acidic, basic, or neutral Write chemical equations to demonstrate how H+ or OH- is generated by the acidic or basic components of these solutions pH equilibrium calculations Based on your answer to question 3, calculate the pH of 0.1 mol/L solutions of the compounds in question Buffers Consider the following mixtures in liter of solution: • 0.10 mol NH3 and 0.1 mol NH4Cl • 0.20 mol acetic acid and 0.4 mol sodium acetate • 0.15 mol HF and 0.10 mol NaF ¾ What are the concentrations of the major species in solution for these mixtures? Based on your answer, calculate the pH of these solutions Acids and Bases Exercise Chemistry 102 Page Acid/Base reactions/stoichiometry Consider the following pairs of compounds: • 0.10 mol NaOH and 0.20 mol HF • 0.15 mol HCl and 0.25 mol NH3 • 0.20 mol HBr and 0.40 mol NaCN • 0.05 mol KOH and 0.10 mol HCl • 0.25 mol NH4Cl and 0.10 mol NaOH ¾ What are the expected major species in solution when each individual member of the pair is dissolved in water? ¾ Classify the major species as strong/weak/pathetic acids/bases If both members of the pair were dissolved in one liter of water, would any of the major species react with one another? Write chemical equations to show the chemical reaction which would occur ¾ After any acidic and basic species react, what is the final concentration of all major species in solution? ¾ Are there now any strong/weak acids/bases left in solution? Calculate the pH of the solution Acid/Base Titrations Consider the following pairs of solutions: • 100 mL of 0.50 mol/L HCl and 50 mL of 0.50 mol/L NaF • 150 mL of 0.25 M NH4Cl and 200 mL of 0.5 mol/L NaOH • 200 mL of 0.10 mol/L HNO3 and 140 mL of 0.20 mol/L NaF • 100 mL of 0.20 mol/L acetic acid and 100 mL of 0.15 mol/L sodium acetate ¾ What are the major species in solution for each individual solution listed? ¾ Classify the major species as strong/weak/pathetic acids/bases If both solutions of each pair were mixed, would any of the major species react with one another? Write chemical equations to show the chemical reaction which would occur ¾ After any acidic and basic species react, what is the final concentration of all major species in solution? ¾ Are there now any strong/weak acids/bases left in solution? Calculate the pH of the solution  ...Acids and Bases Exercise Chemistry 102 Page Acid/Base reactions/stoichiometry Consider the following pairs of compounds: • 0.10