iPad 5:30 PM 53%- . he laboratory exercise you will prepare a series of solution

Question

iPad 5:30 PM 53%- . he laboratory exercise you will prepare a series of solutions of Cu(NHb) from a standard solution of copper (I) nitrate. In one experiment a standard solution was prepared by adding 8.00 mL of 0.09864 M copper (I) nitrate to a 50.00 mL volumetric flask. After the addition of 5.00 mL of 6 M NHs(aq), the solution was diluted to the 50.00 mL mark with deionized water The ammonia added to the flask is in excess of that required to prepare the copper-ammonia complex. a. Use the molarity and volume of the added copper (II) nitrate solution to calculate the number of moles of Cu? added to the volumetric flask. This is accomplished, as you recall, by multiplying the molarity of the solution (mol/L) by the volume of the solution (L) b. Use the number of moles of copper (II) in the volumetric flask and the final volume of the to calculate the concentration (M) of copper (II) in the filled volumetric flask. (In the of excess ammonia all of the copper (II) will be in the form of the copper-ammonia ex ion, Cu(NH)42, so the concentration calculated in part b is the concentration of Ho))

Explanation / Answer

Ans. #a. Number of moles of Cu(NO3)2 = Molarity x Volume of solution in liters

                                                            = 0.09864 M x 0.008 L

                                                            = 0.00078912 mol

#b. 1 mol Cu(NO3)2 dissociates into 1 mol Cu2+ and 2 moles NO3-.

So, moles of Cu2+ taken = 0.00078912 mol

Now,

            [Cu2+] = Moles of Cu2+ / Volume of solution made upto in liters

                        = 0.00078912 mol / 0.050 L

                        = 0.0157824 mol/ L

                        = 0.0157824 M

Therefore, [Cu2+] in 50.0 mL solution = 0.0157824 M

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.