A sufficient amount of NaCN was added to 0.015M AgNO3 to give a solution that was initially 0.100M CN-. What is the concentration of Ag+ in this solution after Ag(CN)2- forms? The formation constant Kf for the complex ion Ag(CN)2- is 5.6x1018.
The formation constant is the equilibrium constant for the
reaction to form the complex, which for this complex is:
Ag+ + 2CN- --> Ag(CN)2-
Kf = [ Ag(CN)2- ] / { [Ag+] [CN-}^2 }
Once you mix the two solutions, the volume is doubled, so each
starting concentration is half in the mixed solution. This means
[Ag+] initial = 0.01 M and [CN-] initial = 0.10 M. Starting there,
you can make a few assumptions.
Since Kf is very large and Ag+ is the limiting reactant,
essentially all of it is converted to complex. Since 1 mole of Ag+
that reacts forms one mole of complex, the concentration of complex
will be essentially 0.010 M after the reaction reaches
equilibrium.
Since nearly all the Ag+ is converted to complex, and two moles of
CN- react for every mole of Ag+ that reacts, the ending
concentration of CN- will be 0.1-2(0.01) = 0.08 M.
Set the ending concentration of Ag+ to the variable z, plug in the
values for each species in the equation for Kf, then solve for
z:
Kf = 5.3 x 10^18 = 0.01 / z(0.08)^2
z = 2.95 x 10^-19.
A sufficient amount of NaCN was added to 0.015M AgNO3 to give a solution that was...
Be sure to answer all parts. Commercial silver-plating operations frequently use a solution containing the complex Ag+ ion. Because the formation constant (Kf) is quite large, this procedure ensures that the free Ag+ concentration in solution is low for uniform electrodeposition. In one process, a chemist added 9.0 L of 5.0 M NaCN to 90.0 L of 0.17 M AgNO3. Calculate the concentration of free Ag+ ions at equilibrium. See your textbook for Kf values. × 10 M (Enter your...
Commercial silver plating operations frequently use a solution containing the complex |Ag(CN)_2] ion. Because the formation constant K_f is quite large, this procedure ensures that the free Ag+ concentration in solution is low to promote uniform electrodeposition. In one process, a chemist added 9.0 L of 1.1M NaCN to 90.0 L of 0.12 M AgN0_3. Calculate the concentration of free Ag+ ions at equilibrium. K_f for this reaction is 1.0 times 10^21. Enter your answer in scientific notation.
28) What is the molar solubility of Mg(OH)2 in a basic solution with a pH of 11.18? Ksp for Mg(OH)2 is 5.6x 10-12 B) 5.6x 10-10 M D) 1.1 x 10-4 M C) 2.4 x 10-6 M A) 5.6 x 10-8 M 29) What is the molar solubility of AgCl in 0.10 M NaCN if the colorless complex ion Ag(CN) 2- forms? Ksp for AgCl is 1.8 x 10-10 and Kf for Ag(CN) 2- is 1.0 x 1021, D) 0.050...
In aqueous solution the Ag+ ion forms a complex with two cyanide anions. Write the formation constant expression (Kf) for the equilibrium between the hydrated metal ion and the aqueous complex. Under that, write the balanced chemical equation for the first step in the formation of the complex.
What is the “free” silver ion concentration in a solution that was (pre-equilibrium) 0.10M AgNO3(aq) and 0.50M NH3(aq)? Kf for [Ag(NH3)2]+ = 1.7x107.
Calculate the equilibrium concentration of Ag+ (aq) in a solution that is initially 0.200 M AgNO3 and 0.200 M KCN. The formation constant for [Ag(CN)2] (aq) is Ka= 1.0 x 10^21. Show your work for each step. a. 5.6 x 10^-22 M b. 5.0 X 10^-22 M c. 3.3 x 10^-33 M d. 1.0 x 10^-30 M e. 1.3 x 10^-21 M
please help What is the approximate concentration of free Cu* ion at equilibrium when 1.57x102 mol copperII) nitrate is added to 1.00 L of solution that is 1.380 M in NH3. For [Cu(NH3)4j2, Kf 2.1 1013 [Cu2 м What is the approximate concentration of free Fe2* ion at equilibrium when 1.42x102mol iron(II) nitrate is added to 1.00 L of solution that is 1.38so M in CN. For [Fe(CN)6]4, Kf=1.0x1035 [Fe"]= In the presence of excess OH, the Al*(aq) ion forms...
Iron(II) nitrate and hydrocyanic acid react to form the hexacyanoferrate(II) ion, [Fe(CN)6] -4 (aq), with a formation constant of 1.438x1035 . This complex ion has an intense blue color in solution . a. If you add 182.734g of iron(II) nitrate solid to 750.0mL of 0.8324M CN-1 (aq) solution, what is the concentration of CN-1 (aq) still in solution when the reaction reaches equilibrium? b. Copper(II) also forms a complex ion with cyanide ions, tetracyanocuprate(II) ion, [Cu(CN)4] -2 (aq), with a...
3. Iron(II) nitrate and hydrocyanic acid react to form the hexacyanoferrate(II) ion, [Fe(CN).]*(aq), with a formation constant of 1.438x10's. This complex ion has an intense blue color in solution. a. If you add 182.734g of iron(II) nitrate solid to 750.0mL of 0.8324M CN'(aq) solution, what is the concentration of CN'(aq) still in solution when the reaction reaches equilibrium? b. Copper(II) also forms a complex ion with cyanide ions, tetracyanocuprate(II)ion, [Cu(CN).] (aq), with a formation constant of 1.028x10”. This complex ion...
We want to determine the concentrations of Ag+, CN-, and Ag(CN)2- when 10.0 mL of 2.00 M KCN is mixed with 10.0 mL of 0.0200 M of AgNO3. Kf for Ag(CN)2- = 1.0 x 1021 a) What is the initial concentration of Ag ion (in M) after mixing but before reaction or equilibrium is established? b) What is the initial concentration of Ag ion (in M) after mixing but before reaction or equilibrium is established?