Part 4: Dissolving Insoluble Solids by Complex ion formation (contd.) 6. Repeat steps 1 through 5 using 0.1 M Mg(NO3)2 instead of 0.1 MZn(NO3)2. 5 . To each of 3 medium test tubes add about 2 mL of 0.1 M Mg(NO3)2. Add one drop of 6 M NaOH to each and stir. Record your observations. . Which compound is precipitated: Now we will try to dissolve this compound, in 3 different ways. 7. To the first test tube add 1 mL of 6 M HCl and stir. Record your observations. Is this observation similar to the observation for Zn? Explain in terms of concentration changes and a shift in equation 1(replace Zn with Mg). 8. To the second test tube add 1 mL of 6 M NaOH and stir. Record your observations. Is this observation similar/ different to the observation for Zn and how ? 9. To the third test tube add 1 mL of 6 M NH3 and stir. Record your observations Is this observation similar/ different to the observation for Zn and how ? 10. How do explain the differences in observations for Zn and Mg compounds in the testube 2 and 3. Hint: Does Mg +2 form complex ions with OH and NH3