This appears to be more work than it really is, i just need help with the domina
ID: 490647 • Letter: T
Question
This appears to be more work than it really is, i just need help with the dominant species and chemical equations.
PART 4 Co(H2O)62+ + 4 Cl1 (aq) CoCl42 (aq) + 6 H2O (l)
1. Place a few crystals of CoCl26H2O into each of three test tubes. Label your test tubes Tube 1, Tube 2and Tube 3
2. Add 2 mL of water to Tube 1 . Stir the crystals to dissolve them into solution. Record these observations:
What is the color of this solution? Red.
What is the dominant species of cobalt in this solution?
Explain your observations with a chemical equation.
3. Add 2 mL of 12 M HCl to Tube 2. Tube 2 will be used steps 36. . Stir the crystals to dissolve them into solution. Record these observations:
What is the color of this solution? Purple
What is the dominant species of cobalt in this solution?
4. Slowly add distilled or deionized water drop by drop with stirring, until no further color change occurs. Record these observations:
What is the color of the solution? Clear
What is the dominant species of cobalt in this solution?
Explain your observations using a chemical equation.
5. Now put Tube 2 into a hotwater bath and observe the color of the solution. Record these observations:
What is the color of the solution at room temperature? Blue
What is the color of the solution in the hotwater bath?
What is the dominant species of cobalt in the hot water bath?
6. Take Tube 2 out of the hotwater bath and place it in an ice bath. Observe the color of the solution.Record these observations:
What is the color of the solution in the ice bath?
What is the dominant species of cobalt in this solution?
Explain your observations using the ideas presented in the Discussion section.
7. Add a few drops of distilled or deionized water to the contents of Tube 3. Tube 3 will be used for steps79. Add just enough water to wet the contents. Don't try to dissolve the salt.Record these observations:
What is the color of the solution? Red
What is the dominant species of cobalt in this solution?
8. Using a test tube holder, heat the contents of the test tube using a Bunsen burner until you aresatisfied that all of the water has been driven off.Record these observations:
What is the color of the solution in the test tube? Blue
What is the dominant species of cobalt in this solution?
Explain your observation using a chemical equation.
9. Add a drop of distilled or deionized water to the contents of the test tube.Record these observations:
What is the color of the solution in the test tube?
What is the dominant species of cobalt in this solution?
Explain your observation using a chemical equation.
Explanation / Answer
2) Co (H2O)6 (aq) <----------> Co +2 so, reddish colour as Co 2+ ions are release into the water.
3) Co(H2O)62+ + 4 Cl1 (aq) CoCl42 (aq) + 6 H2O (l) so, dark blue color due to CoCl42
4) Co(H2O)62+ + 4 Cl1 (aq) CoCl42 (aq) + 6 H2O (l), here on addition of water the equilibrium is shifted towards right. therefore more of Co(H2O)62+ which gives color less solution
5)Co(H2O)62+ + 4 Cl1 (aq) CoCl42 (aq) + 6 H2O (l), here on increasing the temperature the reaction shift towards right side that is product side. so, more of CoCl42 , therefore blue color.