Experimental data for the solubility of lithium chloride (LiCl) and copper(II) sulfate pentahydrate (CuSO4 x 5H2O) & Related Questions

Table 1. Weight data for the solubility of CuSO4 x 5 H2O at various temperatures. (Values are an average of 3 measurements; deviation from the mean does not exceed +/- 3%).

Temperature, oC

Sample volume

Mass of aqueous sample

Mass of dry sample

25

1mL

1.1356 g

0.2034 g

35

1mL

1.1103 g

0.1654 g

45

1mL

1.2359 g

0.3539 g

55

1 mL

1.2418 g

0.3628 g

 

Table 2. Weight data for the solubility of LiCl at various temperatures. (Values are an average of 3 measurements; deviation from the mean does not exceed +/- 3%).

Temperature, oC

Sample volume

Mass of aqueous sample

Mass of dry sample

25

1mL

1.3113 g

0.6022 g

35

1mL

1.3042 g

0.5885 g

45

1mL

1.3146 g

0.6087 g

55

1 mL

1.3064 g

0.5927 g

 

Table 3. Atomic Absorption Spectroscopy data for the solubility of CuSO4 x 5H2O at various temperatures. (Number of replicates = 3)

Temperature, oC

Cu, mg/L

SD

RSD

25

0.7

0.0042

0.62

35

0.8

0.0056

0.68

45

0.9

0.0190

2.01

55

1.0

0.027

2.73

 

Table 4. Titration data for the solubility of LiCl at various temperatures.

Temperature, oC

Sample volume

Molarity of AgNO3

Volume of AgNO3

25

25 mL

0.5000M

V1=33.87mL

V2=34.55mL

V3=34.41mL

35

25 mL

0.5000M

V1=34.76mL

V2=35.06mL

V3=34.79mL

45

25 mL

0.4999M

V1=36.88mL

V2=37.18mL

V3=37.01mL

55

25 mL

0.4999M

V1=36.52mL

V2=36.51mL

V3=36.62mL


Related Questions:

  1. At 110 oC, CuSO4x 5H2O partially dehydrates to produce the mono hydrate, CuSO4 x H2O.
    1. Calculate the concentration of copper (II) sulfate as anhydrous equivalent in the saturated solution as % by mass CuSO4.
    2. Calculate the molar concentration of copper (II) sulfate, CuSO4, as anhydrous equivalent in the saturated solution.
  2. Prepare a graph using the experimental data which plots the concentration by mass of CuSO4 versus the temperature. Using the CRC Handbook of Chemistry and Physics, find data expressing the solubility of CuSO4 in water. Construct a solubility curve plotting this data on the same axes as the experimental data. Compare the curves. How close are they?

  3. List at least 3 possible sources of experimental error that could cause a difference between the experimental data and that reported in the literature.

  4. Using the experimental data, calculate the solubility of CuSO4 as: (grams CuSO4 / 100g H2O).

  5. Write balanced molecular and net ionic equations relating to the titration: 1) for the reaction of LiCl with silver nitrate, 2) the potassium chromate reaction which produces the red color at the end point.

  6. Calculate the concentration of LiCl in a saturated solution at the temperature assigned to you as % by mass of LiCl.

  7. Calculate the concentration of LiCl in a saturated solution at the temperature assigned to you as molar concentration of LiCl.

  8. Using the experimental data, calculate the maximum solubility of LiCl at the temperature assigned to you as grams LiCl /100g H2O.

  9. Compare the solubility curves of LiCl, NaCl, and KCl in the temperature range of 20-600C (Fig. ). Which of the chlorides is the most soluble in water? How does temperature generally affect the solubility of chlorides?

  10. Calculate the molar concentration of CuSO4 using the data obtained by Atomic Absorption (AA) Spectroscopy. Compare the results with the results obtained from weight analysis. Would you recommend using AA spectroscopy as the preferred method for determining the solubility of CuSO4? What might be done to get more accurate results?

  11. Calculate the mean, the deviation from the mean, and the standard deviation for the titration data shown in the Table 4.

  12. Calculate the molar concentration of a saturated LiCl solution at your assigned temperature: first by using titration data and then using weight data from Table 2. Compare your results. Which is more reliable? Explain the reasoning behind your choice.

  13. Plot the concentration of LiCl as mass % versus temperature using: 1) weight analysis data, 2) titration data, 3) data from the CRC Handbook of Chemistry and Physics. Which experimental data are closer to the literature? What method would you recommend for determining the solubility of LiCl in water? How could the physical properties of LiCl affect the accuracy of weight analysis?