This is for the lab practical I take on Tuesday night. If youcould answer each one and show your work/ explain that'd be amazingso I can do well on the actual practical on Tuesday! Thank you!

Chemistry 211   Lab Final Study Guide  Spring 2015

Useful Information:
1 ampere =coulomb/sec
Faraday’s constant = 96,500 coulombs/mole of electrons
Molar mass of Au = 197.0 g/mole, Molar mass of Cu = 63.55g/mole
m = moles ,   '   ’

c   kg

ΔTf

= Tf

− Tf

where Tf is for the pure solvent and Tf

is for the mixture.

ΔT = (K

)(m ) ,

m = (

(mass of

solute, g )
)(   ).

f   f   c

c   molar

mass, g

mol −1

mass of

solvent, kg

7.   Next question

(a)   If you weigh 6.355 grams of copper, addconcentrated nitric acid to dissolve it, and then dilute thesolution to a total volume of 50 mL, how many moles of copper arein this solution?

(b)   For the equilibrium reaction 3H2(g) + N2(g) →2NH3(g), what is the equilibrium constant expression, Kc, for thisreaction? (5pts)

8.   Suppose at some temperature, the equilibriumconcentration of H2 is 0.45M, the equilibrium concentration of N2is 0.38M, and the equilibrium concentration of NH3 is 0.42M. Whatis the value of the equilibrium constant for the reaction 3H2(g) +N2(g) → 2NH3(g) at this temperature? (Show your work. No creditwill be given if your work is not shown.)

9.   Next question
(a)   If you need 0.0534 moles of NaOH to reachequivalent point in the titration with acetic acid, how many mL of0.09876M NaOH will you need?

(b)   The Ksp of Cu(OH)2 is 2.2x10-20, what is thesolubility of Cu(OH)2?

10.   Next question
(a)   In non-sulfide qualitative analysis ofrepresentative cations, the Group A cations comprising of Pb2+,

Hg2+, and Ag+ give a precipitate with  solution.
(b)   From a solution containing mixture of Pb2+, Fe3+,and Al3+, Pb2+ is removed by adding HCl solution. To the remainingcation mixture, on making the solution basic with NH3 (pH=9 – 10),both the cations form precipitate. Further analysis of the cationmixture containing Fe3+ and Al3+ is carried out by adding NaOHsolution.

Aluminum hydroxide    (dissolves/remains undissolved) inNaOH solution while Ferric hydroxide       ( dissolves/remains undissolved).
(c)   Fe(OH)3 precipitate is dissolved in minimal amountof aqueous HCl which gives a

yellow solution. To this solution addition of    solution(at pH = 4 – 5) yields a dark blue solid known as PrussianBlue.

(d)   Describe the method for checking forcompleteness of precipitate in qualitative analysis of ions.