e) [A] = [B] at equilibrium. 4. A0.10 M aqueous solution of which of the followi
ID: 697772 • Letter: E
Question
e) [A] = [B] at equilibrium. 4. A0.10 M aqueous solution of which of the following salts will have the highest pH? a)Ca(CO)2 b) BaBr2 c)Al(CIO4)s d) NHal e) RbNO 5. What is the pH of a 0.46 M propanoic acid (HCsHs02) solution? For HC3Hs02, K 1.3 10 a) 0.34 b) 227 c)2.61d) 5.22 e)11.39 6. If you add 4.95 g NaCHsCO2 to 250 mL of a 0.150 M CH3CO2H solution, what is the pH of the resulting buffer solution? For CH3CO2H, K 1.8x10- a) 0.824 b) 2.79 c)4.54 d) 4.95 e)9.05 a) 3.6x10-9 M b) 48 10-9 M c) 6.3 10-9 M d) 8.2 109M e) 3.9 10-7 M MgCl2 and 500.0 mL of 1.2x10 M NaF? 7 What is the molar solubility of Al(OH)s in pure water? Kap = 4 6x10-33 for Al(OH)3. 8. For MgF2, Ksp-6.9x 10 Does a MgF2 precipitate form if you mix 300.0 mL of 1.1x103M a) no precipitate forms because Q > Ksp b) no precipitate forms because Q Kp d) a precipitate forms because Q Ksp e) no precipitate forms because Q Kap 9 AG"--95 kJ for a roacton at 25 °C Calculate the equilibrium constant, K, at 25 a) 1.04 b) 2 2 103 c) 4.9 10 d) 2.2 10 1" e) 4 5 101"Explanation / Answer
4) Ca(ClO)2 is a salt of weak acid(HClO) and strong base((Ca(OH)2) and produces basic solution in water. Hence it has high pH value
ANswer A
5) pH = -log[H+]
[H+] = sqrt(Ka*C) = sqrt(1.3*10^-5*0.46) = 0.00245 M
pH = -log(0.00245) = 2.61
Answer C
6) Molarity of NaCH3CO2 = (mass/molar mass)(1000/V(mL))
M = (4.95/82)(1000/250) = 0.24 M
[NaCH3CO2] = 0.24 M
[CH3COOH] = 0.150 M
From Henderson equation, pH of buffer solution is given by
pH = Pka+log[salt]/[acid]
pH = 4.74+log(0.24/0.15) = 4.95
Answer D
7) Al(OH)3 ==== Al^3+ + 3OH-
Ksp = [Al^3+][3OH-]^3 = (x)(3x)^3 = 27x^4
4.6*10^-33 = 27x^4
x = 3.6*10^-9 (Answer A)
8) MgF2 ==== Mg^2+ + 2F-
Ksp = [Mg^2+][F-]^2
[Mg^2+] = (1.1*10^-3/0.8L) = 0.00138 M
[F-] = (1.2*10^-3/0.8) = 0.0015 M
Q = (0.00138)(0.0015)^2 = 3.1*10^-9
Ksp of MgF2 = 6.9*10^-9
Therefore, Ksp > Q, no precipitation occurs
Answer B
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.