b) What is the approximate pH at the equivalence point of (b) curve? Express your answer as a whole number. c) Which curve corresponds to the titration of the strong base and which one to the weak base? Your Answer: a) By obsreving the titration curves we conclude that thesolition of the curve a) curve may contains pH atapproximately 7 . b) pH approximately 5 c) Graph (a) represents a strong base and graph (b) represents a weak base.
Question 7 Not yet graded / 10 pts Use K sp = 4.87 × 10 −17 to calculate the solubility of iron (II) hydroxide in pure water in grams per 100.0 mL of solution. Your Answer: The reaction is Fe(OH) 2 <-------> Fe +2 + 2OH - K sp = [Fe 2+ ][OH - ] 2 4.87 x 10 -17 = [Fe 2+ ][OH - ] 2 = (x)(2x) 2 = 4x 3 x = molar solubility = 2.30 x 10 -6 M mass Fe(OH) 2 = 2.30 x 10 -6 mol/L x 0.100 L x 89.86 g/mol= 2.07 x 10 -5 g Question 8 Not yet graded / 10 pts Here is the chemical reaction that represents solid lead sulfate dissolving in water: PbSO 4 (s) ⇌ Pb 2+ (aq) + SO 4 2− (aq) Ksp = 1.8 × 10 −8 Which of the following actions would shift this reaction toward solid lead sulfate? a.) Add more lead sulfate. b.) Add more sulfate ions. c.) Remove sulfate ions. d.) Remove lead ions. In which of the following would lead sulfate be least soluble? a) pure water b) 1 M KNO 3 c) 1 M Na 2 SO 4 In which of the following would lead sulfate be most soluble?
a) 1 M NaNO 3 b) 1 M H 2 SO 4 c) 1 M Pb(NO 3 ) 2 d) 1 M CuSO 4 Which action would shift this reaction away from solid lead sulfate and toward the dissolved ions?
You've reached the end of your free preview.
Want to read all 7 pages?
- Fall '09
- pH, HOBr, solid lead sulfate