Question

Analytical

i. As the ionic strength, μ +0, activity coefficient, γ activity - The pH of a 3.22 x 102 M solution of Sr(OH)2 is ii. The activity coefficient of Fe3t at μ = 0.075 (aFe"-o9 nm) is Write the ACCURATE expressions for the equilibrium constants, K, for the reaction below in terms of activity coefficients and concentrations. v. CaF2(s) + 2 H2O() Ca2"(aq) + 2 HF (aq) + 2 OH (aq) v. Which of the following is the strangest acid? Cions acs_ cyanic acid, HOCN, (Ka-3.5 x 10 Lactic acid, HCH,Os, (Ka 1.3x 10) Benzoic acid, HC,HsO2, (K- 6.3 x 10- Formic acid, HCHO, (K 1.7 x 10) Propionic acid, HCtho, (Ka-1.3x 10-5) vi. Write a reaction between bisulfite, HSOs, and ammonium ion, NHs', and identify the acid, base, conjugate acid, and conjugate base. a) Reaction:WSoN WSo b) b) Acid: uc Base: Hso d)Conjugate acid-wAOg e) Conjugate base w vii. Write the chemical reaction whose equilibrium constant is Ka for anilinium ion CaHsNH' vili. A buffer could be prepared from 0.100 M ammonia, NHa, by adding to the solution. or # 0.020). Find Kof the base. ix. A 0.10 M solution of a base is 2.0 % hydrolyzed (

Answer 1

Alpha ion = f_z middot c_ion equation (1) f_z denotes the activity coefficient i) as mu or I = 1/2 Sigma Li Zi^2 ionic strength as mu rightarrow 0 Cion rightarrow 0 and f_z rightarrow 1 activity from 1st relation rightarrow 0 ii) Sr(OH)_2 3.22 times 10^-2 m Sr(OH)_2 rightarrow Sr^2 + + 2OH^- Concn of (OH^-] = 2 times 3.22 times 10^-2 pOH = -log 6.44 times 10^-2 = -(log 6.44 + log 10^-2) = -(0.808 - 2) = 1.192 pH = 12.808 iii) CaF_2(s) + 2H_2O(l) rightleftarrow Ca^2 + (aq) + 2HF(aq) + 2OH^-(aq) K_c = r_Ca^2 + middot [Ca^2 +] middot r_HF middot (HF] times [r_OH^- (OH^-]]^2 iv) as ka uparrow acidic strength uparrow therefore cyanic acid HOCN is strongest acid. \r\n v) C_6 H_5 NH_3 rightleftarrow H^+ + C_6 H_5 NH_2 K_a = [H^+] times [C_6 H_5 NH_2]/[C_6 H_5 NH_3^+] vi) by adding 0.05 M Hcl as NH_3 + HCl rightarrow NH_4Cl t = 0 0.1 m 0.05m