Question

6) Magnesium hydroxide is added to water. What do you observe? What changes, if anything, when excess 5M HCl is added? What changes, if anything, when excess 5M NaOH is added to the newest solution? Explain in terms of Le Chatelier’s Principle and solubility rules.

7) When CuSO4·5H2O is added to water, it dissolves to form a blue solution. What happens when hexane is added on top and the solution is shaken? Write a separation scheme to show.

8)When I2 is added to water, it dissolves to form a reddish-brown solution. What happens when hexane is added on top and the solution is shaken? Write a separation scheme to show

Answer 1

#6. Magnesium hydroxide is insoluble in water , so when we add Mg(OH)2 to water it settles down in the bottom.

Then after adding excess 5M HCl ; Mg(OH)2 get neutralized and dissolves in HCl and you observe clear solution as ;

Mg(OH)2(s) + 2HCl(aq) >>>>> MgCl2(aq) + 2H2O(l)

Again if you add excess 5M NaOH , the magnesium hydroxide again precipitates out and you will again observe insoluble white Mg(OH)2 precipitates as ;

MgCl2(aq) + 2NaOH(aq) >>>>> Mg(OH)2(s) + 2NaCl(aq)

answered by: anonymous