for ANALCHEM EXAM

Notes: No erasure(s)/ALTERATIONS; if so, only 1 point will be given for every correct answer!

                                                                               

I.                    IDENTIFICATION : 2 POINTS (pts.) each number 

__________ 1. Expresses the amount of solute in mole per kilogram of solvent.

__________ 2. Type of change if solution gives off energy to the environment.

__________ 3. Expresses the amount of solute in moles per liter of solution.

__________ 4. Number  of equivalent of solute per liter of solution.

__________ 5. Type of change that absorbs energy from the environment.

II.                  Assign Oxidation Number (ON) on the following:

1.      NaMnO₄                       Na __, Mn __, O __

2.      SnO₂                  Sn __, O __

III.              Classify each of the following ½ reactions as oxidation or reduction

1.      NH₄ ⁺    →        N₂                                __________

2.      CH₃OH →        CH₂O                           __________

IV.                Balance the following REDOX equations using half-reaction method:

A.    Fe ²⁺      +      MnO₄ ^-     →      Fe ³⁺      Mn ²⁺      (acidic)

B.      Cl₂     +     Cr (OH)₃        →      Cl ^-     +     CrO₄ ^2- (basic)

Balance the equation by adding electrons either to the reactant side or product side.

1.    MnO₄ ^-     →     Mn ²⁺                  (acidic)

2.      Cr (OH)₃ →      CrO₄ ^2-        (basic)

V.                  Concentrations of  Solution:No solution, no credit points!Total points = 15 pts.

1.       How many grams of NaCl are present in a 750.0 g of salt solution containing of 8% NaCl?

2.       A solution is prepared by reacting 90 mL of C₂H₅OH in 500 mL of distilled water. What is the % v/v concentration and the proof number of the solution.

3.       A 2.20 % (m/v) sugar solution has to be administered a patient intravenously. Find the mass of sugar required to prepare 344 mL of this solution.