A 0.512 g sample of CaCO3 is dissolved in 12 M HCl and the mixture is diluted to 250 mL. A small amount of MgCl2 solution is added to a 25 mL aliquot of the solution., and the mixture is titrated with (ethylenediaminetetraacetic acid) EDTA to the Eriachrome Black T (with MgCl2 is used as indicator) end point. The mixed solution requires 28.55 mL of the EDTA solution to reach the end point. A similar amount of MgCl2 solution requires 2.60 mL to reach the endpoint. A 100-mL sample of hard water is titrated with 22.4 mL of the EDTA solution created above. The same amount of MgCl2 is added as previously and the total volume of EDTA solution required is 22.44 mL. a) Assume all of the Ca2+ in the water comes from CaCO3. How many moles of CaCO3 are in 1 L of water? How many grams of CaCO3 are in 1 L of water? c) If 1 ppm CaCO3 = 1 mg/liter, what is the water hardness in ppm CaCO3 ?

A 0.512 g sample of CaCO3 is dissolved in 12 M HCl and the mixture is diluted to 250 mL. A small amount of MgCl2 solution is added to a 25 mL aliquot of the solution., and the mixture is titrated with (ethylenediaminetetraacetic acid) EDTA to the Eriachrome Black T (with MgCl2 is used as indicator) end point. The mixed solution requires 28.55 mL of the EDTA solution to reach the end point. A similar amount of MgCl2 solution requires 2.60 mL to reach the endpoint. A 100-mL sample of hard water is titrated with 22.4 mL of the EDTA solution created above. The same amount of MgCl2 is added as previously and the total volume of EDTA solution required is 22.44 mL. a) Assume all of the Ca2+ in the water comes from CaCO3. How many moles of CaCO3 are in 1 L of water? How many grams of CaCO3 are in 1 L of water? c) If 1 ppm CaCO3 = 1 mg/liter, what is the water hardness in ppm CaCO3 ?

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter16: Applications Of Neutralization Titrations

Section: Chapter Questions

Problem 16.41QAP

See similar textbooks

Similar questions

A 0.512 g sample of CaCO3 is dissolved in 12 M HCl and the mixture is diluted to 250 mL. A small amount of MgCl2 solution is added to a 25 mL aliquot of the solution., and the mixture is titrated with (ethylenediaminetetraacetic acid) EDTA to the Eriachrome Black T (with MgCl2 is used as indicator) end point. The mixed solution requires 28.55 mL of the EDTA solution to reach the end point. A similar amount of MgCl2 solution requires 2.60 mL to reach the endpoint. A 100-mL sample of hard water is titrated with 22.4 mL of the EDTA solution created above. The same amount of MgCl2 is added as previously and the total volume of EDTA solution required is 22.44 mL. a) What volume of EDTA is used in titrating the Ca2+ in the hard water? b) How many moles of EDTA are there in that volume? c) How many moles of Ca2+ are in 100 mL of water?
A 0.512 g sample of CaCO3 is dissolved in 12 M HCl and the mixture is diluted to 250 mL. A small amount of MgCl2 solution is added to a 25 mL aliquot of the solution., and the mixture is titrated with (ethylenediaminetetraacetic acid) EDTA to the Eriachrome Black T (with MgCl2 is used as indicator) end point. The mixed solution requires 28.55 mL of the EDTA solution to reach the end point. A similar amount of MgCl2 solution requires 2.60 mL to reach the endpoint. A 100-mL sample of hard water is titrated with 22.4 mL of the EDTA solution created above. The same amount of MgCl2 is added as previously and the total volume of EDTA solution required is 22.44 mL. How many moles of Ca2+ are in 100 mL of water?
A 0.512 g sample of CaCO3 is dissolved in 12 M HCl and the mixture is diluted to 250 mL. A small amount of MgCl2 solution is added to a 25 mL aliquot of the solution., and the mixture is titrated with (ethylenediaminetetraacetic acid) EDTA to the Eriachrome Black T (with MgCl2 is used as indicator) end point. The mixed solution requires 28.55 mL of the EDTA solution to reach the end point. A similar amount of MgCl2 solution requires 2.60 mL to reach the endpoint. How many milliliters of EDTA are needed to titrate the Ca2+ ion in the sample? How many moles of EDTA are there in the volume calculated for the question above? What is the molarity of the EDTA solution?
A 1.250 g sample of cheese was subjected to KKjeldahl analysis to determine the amount of protein. the sample was digested and the nitrogen is oxidized to NH4+ and was then converted to NH3 with NaOH., and distilled into a collection flask containing 50.00 mL of .1050 M HCl. The excess HCl is back titrated with .1175M NaOH, this required 21.65 mL to reach the bromothymol blue endpoint. What is the reaction for the back titration for this analysis and the %N of cheese sample.
A 2.054 g of macrogol monostearate (average molecular weight 706. 5) was added to a 200 ml flask and 25 ml of an ethanolic solution of potassium hydroxide (molecular weight 56.1, ca 0.5 M) was added. The sample was heated under a reflux condenser for 1 hour. The excess of alkali was then titrated with 0.5016 M hydrochloric acid using phenolphthalein solution as an indicator. The operation was repeated without the macrogol monostearate. Results Volume of HCI required to titrate the excess alkali = 18.35 ml Volume of HCI required to titrate the blank = 24.03 ml Calculate the saponification value for the macrogol stearate. Answer: Blank mg/g
A 0.3045 g of CaCO3 primary standard was dissolved using concentrated HCl, evaporated to incipient dryness, and quantitatively transferred to a 250 mL volumetric flask and diluted to mark. A 10 mL of aliquot was then transferred to an Erlenmeyer flask, together with 5mL buffer and 5 drops of EBT indicator, and was used to standardize the EDTA titrant. The solution turned blue after the addition of 24.10 mL of EDTA. A blank correction was made and was determined to be 0.4 mL. [Analysis] A 30 mL unknown water sample was treated with 37.6 mL of EDTA. A blank correction was made and was determined to be 0.4 mL. What is the concentration of Ca2+ (40.0780 g/mol) in ppm?
If a 25.00 ml aliquot of a solution containing sulfide ions was added to 25.00 ml of 0.0103 M Cu2+ solution. The CuS precipitate was washed and collected. The pH of the combined filtrate and washings was then adjusted by the addition of ammonia and the solution was titrated with 0.01453 M EDTA, using a suitable indicator. The endpoint volume was found to be 12.20ml. Find the molarity of the sulfide in the sample solution.
The sulfate in a247.1 mg sample was precipitated as BasO4 by addition of 25.00 mL of 0.03992 M BaCl2. The precipitate was removed by filtration and the remaining BaCl2 consumed 36.09 mL of 0.0217 M EDTA for titration to the Camalgite endpoint. Calculate the % SO3 in the sample.
A solid containing tris was dissolved in water and brought to a total volume of 50.00 ml. A 10.00 ml aliquot of the solution was titrated with 0.09978 M HCl to a bromcresol green endpoint. The aliquot consumed 38.93 ml of titrant. Calculate the weight of tris in the original sample.
10mL of a 10% by weight MgCl2 solution (density = 1.1 g / mL) is precipitated as magnesium ammonium phosphate after necessary processes, filtered and washed. The precipitate is dissolved in 50mL 1M HCl and excess acid is titrated with 2.0M NaOH solution in the presence of methyl orange. Find the NaOH consumption (Mg = 24,3g / mol, Cl = 35,5g / mol)
An aqueous solution of 0.2100 g of a mixture containing potassium cyanide and potassium chloride required 14.56 mL of 0.1000 M silver nitrate to produce a faint permanent turbidity; 30.00 mL more of the silver nitrate was added (an excess) and the precipitate of AgCl and AgCN filtered off from the solution. The filtrate and washings were titrated with 13.06 mL 0.1000 M thiocyanate solution. Calculate the percentages of KCl and KCN in the sample.
1ml of 1mg/ml of diluted aspirin powder solution is titrated by 0.005M NaOH. Before titration, 5 ml ethanol, 14 ml CO2 free water, and 4 drops bromothymol blue indicator is added into diluted aspirin powder solution. Mass of 0.005M NaOH used is obtained by weight titration = 1.1384g . [Molar mass of aspirin =180.15]; for solution, 1g=1mL at 25 degree Celcius. Calculate the purity of the powder.