Question

In: Chemistry

to a 100.0 mL volumetric flask are added 1.00 mL volumes of three solutions: .0100 M...

to a 100.0 mL volumetric flask are added 1.00 mL volumes of three solutions: .0100 M AgNO3, .205 M NaBr, and .100 M NaCN. The mixture is diluted with deionized water to the mark and shaken vigerously. What mass of AgBr would precipitate from this mixture? Hint: The Ksp of AgBr is 5.4 x 10-13 and the Kf of Ag(CN)2- is 1.0 x 10^21

Expert Solution

Moles of AgNO3 (OR moles of Ag+ ) = Molarity X Volume = 0.01 X 1mL = 0.01mmoles

Molarity of AgNO3 when the solution is diluted to 100mL = 0.01mmol / 100mL = 1.0 X 10^-4M

Similarly Moles of NaBr (Or moles of Br-) = 0.205 X 1mL = 0.205mmol

Molarity = 0.205mmol/100mL = 2.05 X 10^-3M

Moles of NaCN = 0.1mmol

Molarity = 0.1mmol / 100mL = 1.0 X 10^-3 M

Since Kf is very large hence almost all the Ag+ will be in complex form Ag(CN)2-

Ag+ will react with CN-

Ag+ + 2CN^- -------> Ag(CN)₂^-

I 1.0 X 10^-4M ---1.0 X 10^-3M --------- 0

C -1.0 X 10^-4M --- -2X1.0 X 10^-4M -------- 1.0 X 10^-4M

E 0 ------- 8 X 10^-4 --------1.0 X 10^-4M

From above ICE equation it is obvious that all the Ag+ is consumed in Ag(CN)2- formation. The only Ag+ available will be from dissiciation of the cyanide complex

Ag(CN)2- <------>. Ag+ + 2CN-

At Equlibrium 1.0 X 10^-4M - x ------------ +x ------- 8 X 10^-4+2x

Kr = 1/Kf = 1.0 X 10^-21 = [Ag+][CN-]² / [Ag(CN)2-]

1.0 X 10^-21 = [x][8 X 10^-4+2x]² / [1.0 X 10^-4M - x ]

Kr is so small that the above equation can be simplified as

1.0 X 10^-21 = [x][8 X 10^-4 ]² / [1.0 X 10^-4M ]

x = 1.0 X 10^-21 X [1.0 X 10^-4M ] / [8 X 10^-4 ]² = 1.56 X 10^-11.

PPt of AgBr

Ag+ + Br- <----> AgBr

Qsp = [Ag+] [Br-] = 1.56 X 10^-11 X 2.05 X 10^-3 = 3.198 X 10^-14

Since Qsp < Ksp no precipitation will take place

1.0 x 10²¹ = [Ag(CN)₂^-] / [1.0 X 10^-4][1.0 X 10^-3M]²

[Ag(CN)₂^-] = 1.0 x 10²¹

queen_honey_blossom answered 1 year ago

To a 250.0 mL volumetric flask are added 1.00 mL volumes of three solutions: 0.0100 M...

To a 250.0 mL volumetric flask are added 1.00 mL volumes of three solutions: 0.0100 M AgNO3, 0.150M NaBr, and 0.100 M NaCN. The mixture is diluted with deionized water to the mark and shaken vigorously. The Ksp of AgBr is 5.40×10–13 and the Kf of Ag(CN)2– is 1.00×1021. What mass of AgBr would precipitate from this mixture? Do not simply write "0" as some precipitate will form.

To a 150.0mL volumetric flask are added 1.00 mL volumes of three solutions: 0.0100 M AgNO3,...

To a 150.0mL volumetric flask are added 1.00 mL volumes of three solutions: 0.0100 M AgNO3, 0.225 M NaBr, and 0.100 M NaCN. The mixture is diluted with deionized water to the mark and shaken vigorously. What mass of AgBr would precipitate from this mixture? (Hint: The Ksp of AgBr is 5.4x10-13 and the Kf of Ag(CN)2- is 1.0x1021)

To a 100.0mL volumetric flask are added 1.00 mL volumes of three solutions: 0.0100 M AgNO3,...

To a 100.0mL volumetric flask are added 1.00 mL volumes of three solutions: 0.0100 M AgNO3, 0.190 M NaBr, and 0.100 M NaCN. The mixture is diluted with deionized water to the mark and shaken vigorously. What mass of AgBr would precipitate from this mixture? (Hint: The Ksp of AgBr is 5.4x10-13 and the Kf of Ag(CN)2- is 1.0x1021)

To a 100.0 mL volumetric flask were added 7.00 mL of 1.70 M of H3VO4, 1.401...

To a 100.0 mL volumetric flask were added 7.00 mL of 1.70 M of H3VO4, 1.401 g of NaH2VO4, and 15.00 mL of 1.5 M NaOH. The flask was filled to the calibration mark with water. What were the molar concentrations of H+, OH-, the two other relevant molecules and the pH of the solution? Is the resulting solution a buffer? Ka1 = 1.0 x 10-4, Ka2 = 2.8 x 10-9 and Ka3 = 5.0 x 10-15 for H3VO4.

You have available 1.00 L volumes of the three following solutions: 1.00 M HCl, 1.00 M...

You have available 1.00 L volumes of the three following solutions: 1.00 M HCl, 1.00 M NaOH and 1.00 M NaH2PO4. You wish to prepare 500.0 mL of a buffer solution that maintains a pH of 2.50. Indicate which two of these three solutions you would use to produce this buffer, and calculate the volume of each of these two solution you would need to mix to get the desired volume and pH value for the buffer.

A 100.0 ml sample of 1.00 M NaOH is mixed with 50.0 ml of 1.00 M...

A 100.0 ml sample of 1.00 M NaOH is mixed with 50.0 ml of 1.00 M H2SO4 in a large Styrofoam coffee cup; the cup is fitted with a lid through which passes a calibrated thermometer. the temperature of each solution before mixing is 22.9°C. After adding the NaOH solution to the coffee cup and stirring the mixed solutions with thermometer; that the specific heat of the mixed solutions is 4.18 J/(g•°C), and that no heat is lost to the...

10 mL of bleach with an unknown concentration is added to a 100mL volumetric flask. The...

10 mL of bleach with an unknown concentration is added to a 100mL volumetric flask. The solution is then finished with deionized water. 10 mL of this diluted bleach solution is then added to an erlenmeyer flask along with 1 scoop of KI, and 5 L of 2M HCl. This solution is then titrated with Na2S2O3 until it is a pale yellow color, then a starch indicator is added and titration is completed until the solution is clear. If 43...

A solution of 100.0 mL of 1.00 M malonic acid (H2A) was titrated with 1.00 M...

A solution of 100.0 mL of 1.00 M malonic acid (H2A) was titrated with 1.00 M NaOH. K1 = 1.49 x 10-2, K2 = 2.03 x 10-6. What is the pH after 50.00 mL of NaOH has been added?

When 10.0 mL of 1.00 M AgNO3 solution is added to 10.0 mL of 1.00 M...

When 10.0 mL of 1.00 M AgNO3 solution is added to 10.0 mL of 1.00 M NaCl solution at 25.0 ° C in a calorimeter, a white precipitate of AgCl forms and the temperature of the aqueous mixture increases to 32.6 ° C. Assuming that the specific heat of the aqueous mixture is 4.18 J/(g °C), the density of the mixture is 1.00 g/mL, and the calorimeter itself absorbs a negligible amount of heat, what is ΔH in kJ/mol AgCl...

these solutions (2-5) will each be in their own 50 mL volumetric flask. assigned pH for...

these solutions (2-5) will each be in their own 50 mL volumetric flask. assigned pH for buffer system: 4.75 acid/base pair to use: acetic acid and sodium acetate concentration of acetic acid amount of acid to add concentration of sodium acetate amount of base to add unit molarity g or mL (circle one) molarity g or mL (circle one) solution 2 0.05 0.5 solution 3 0.10 0.5 solution 4 0.50 0.05 solution 5 0.50 0.10 Sample calculation for acid (solution...