Question

In: Chemistry

Solutions of chromate are yellow in colour. At concentrations above 2.5 × 10-3 M, the sample...

Solutions of chromate are yellow in colour. At concentrations above 2.5 × 10-3 M, the sample solution is sufficiently coloured such that the observance of the red precipitate is masked. Calculate the relative error in the volume of titrant added that would be observed for the titration of an unknown chloride solution containing 2.5 × 10-3 M chromate with 0.1 M AgNO3. Assume that 25 mL of titrant is required to reach the endpoint, where the total solution volume will be 1 litre.

Solutions

Expert Solution

We have,

Ksp of AgCl = 1.82 x 10-10

Therefore,

Concentration of Ag at the equivalence point = (1.82 x 10-10)1/2 = 1.34 x 10-5M

Also,

Ksp of Ag2CrO4 = 1.1 x 10-12

Therefore,

[Ag+]2 = Ksp/[CrO42-] = (1.1 x 10-12)/(2.5 x 10-3) = 4.4 x 10-10

[Ag+] = 2.1 x 10-5 M

Error in concentration = Moles of excess Ag = 2.1 x 10-5 – 1.34 x 10-5 M = 7.6 x 10-6 M

Error in the volume of titrant added =   [(Moles of excess Ag)/Concentration of titrant] x 1000ml/L

                                                          = [(7.6 x 10-6 M)/0.1 M] x 1000 mL/L = 0.08 mL

If 25 mL was used to reach the endpoint, then

Percent error = (0.08/25) x 100% = 0.32 %       


Related Solutions

Calculate the pH of solutions with the following concentrations. A: [H3O+] = 1×10−12 M Express your...
Calculate the pH of solutions with the following concentrations. A: [H3O+] = 1×10−12 M Express your answer using one decimal place B: [OH−] = 1×10−5 M Express your answer using one decimal place. C; 3.00×10−3 mol of HBr are dissolved in water to make 16.0 L of solution. What is the concentration of hydroxide ions, [OH−], in this solution? Express your answer with the appropriate units. D: 8.00 g of NaOH are dissolved in water to make 4.00 L of...
There are two sodium acetate solutions. Their apparent concentrations are 1.00 x 10^-1 M and 1.00...
There are two sodium acetate solutions. Their apparent concentrations are 1.00 x 10^-1 M and 1.00 x 10^-10 M, respectively. Please find the pH and true concentration (M) of acetic acid, and sodium acetate in these two solutions, respectively. The pKa of acetic acid is 4.75. Also, can you use the same indicator for the following titration? Why? Please reason your answers with at least two criteria. (a) HCl titrated by NaOH, and (b) NaOH titrated by HCl.
Determine the pH of each of the following two-component solutions. 1)4.5×10−2 M KOH and 2.5×10−2 M...
Determine the pH of each of the following two-component solutions. 1)4.5×10−2 M KOH and 2.5×10−2 M Ba(OH)2 2)0.265 M NH4NO3 and 0.102 M HCN 3)7.5×10−2 M RbOH and 0.120 M NaCl 4)9.2×10−2 M HClO4 and 2.2×10−2 M KOH 5)0.115 M NaClO and 5.50×10−2 M KI
Determine the pH of each of the following two-component solutions. 1)4.5×10−2 M KOH and 2.5×10−2 M...
Determine the pH of each of the following two-component solutions. 1)4.5×10−2 M KOH and 2.5×10−2 M Ba(OH)2 2)0.265 M NH4NO3 and 0.102 M HCN 3)7.5×10−2 M RbOH and 0.120 M NaCl 4)9.2×10−2 M HClO4 and 2.2×10−2 M KOH 5)0.115 M NaClO and 5.50×10−2 M KI
if a titration using these solutions started with 25.00 mL of potassium chromate solution (0.5056 M),...
if a titration using these solutions started with 25.00 mL of potassium chromate solution (0.5056 M), what volume of 0.2456 M lead (II) nitrate solution would be required to reach the end point? what MASS of the products would be created in that reaction?
A 280.0 −mL buffer solution initially contains 2.5×10−2 M of HCHO2 and 2.5×10−2 M of NaCHO2....
A 280.0 −mL buffer solution initially contains 2.5×10−2 M of HCHO2 and 2.5×10−2 M of NaCHO2. a,) In order to adjust the buffer pH to 4.10, should you add NaOH or HCl to the buffer mixture? The answer is: NaOH b.) What mass of the correct reagent should you add?
For the following equilibrium: C2H2+2Br2⇌C2H2Br4 If the initial concentrations are: [C2H2]=0.25 M,[Br2]=0.50 M,[C2H2Br4]=2.5 M , and...
For the following equilibrium: C2H2+2Br2⇌C2H2Br4 If the initial concentrations are: [C2H2]=0.25 M,[Br2]=0.50 M,[C2H2Br4]=2.5 M , and the reaction proceeds in the reverse direction until equilibration, where [ C2H2Br4]=2.15 M , what is the final concentration of Br2 ? 0.50 0.85 1.2 0.15
Silver chromate is sparingly soluble in aqueous solutions. The Kşp of Ag2CrO4 is 1.12 x 10-12 M3.
Silver chromate is sparingly soluble in aqueous solutions. The Kşp of Ag2CrO4 is 1.12 x 10-12 M3. What is the solubility (in moles per liter) of silver chromate in a 1.00 M potassium chromate aqueous solution? What is the solubility (in moles per liter) of silver chromate in a 1.00 M silver nitrate aqueous solution? What is the solubility (in moles per liter) of silver chromate in pure water? 
Calculate the pH of the following solutions: (a) 10-3 M HClO4 (note that for HClO4 the...
Calculate the pH of the following solutions: (a) 10-3 M HClO4 (note that for HClO4 the pKa = -7) (b) 10-3 M HOCl (note that for HOCl the pKa =7.52) (x) 10-6.5 M NaOH (d) 10-3 M NH4Cl (note that for NH4+ the pKa =9.25)
Silver chromate is more soluble in solutions containing some (less than 1 M) potassium nitrate, even...
Silver chromate is more soluble in solutions containing some (less than 1 M) potassium nitrate, even though neither potassium nor nitrate show up in the BCE for the dissolution reaction Ag2CrO4 (s) ↔ 2 Ag+(aq) + CrO4 2-(aq) The solubility product constant (which is not the same as the solubility!) for silver chromate is Ksp = 1.1 x 10-12 making it a pretty insoluble substance. Your job is to figure out the molar solubility in pure water, then the molar...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT