Monday, December 19, 2016

ANALYTICAL CHEMISTRY FINAL EXAM

LSPU – Los Banos Campus          FINAL EXAM                        ANALYTICAL CHEMISTRY
Notes: No erasure(s)/ALTERATIONS; no solution for problem set, no credit points!
NOTES:For part I,III and IX, 2 pts. each number; no answer means negative one point. No erasures/alterations in your Answer Sheet (AS) .If so, ¼ point (0.25) each will be deducted from the actual score. GOOD LUCK!
I.                    Modified TRUE OR False :Write TRUE if the statement is correct. If it’s false, change the underlined word  by writing on the AS the appropriate term that makes the statement right.

_____ 1. A strong acid will react with a strong base to form acidic solution.
_____ 2. Titrant or titrator is a standard solution of known concentration.
_____ 3. A strong acid will react with a weak base to form a neutral solution.
_____ 4. A weak acid will react with a strong base to form a basic solution.
_____ 5. Sodium hydroxide is highly insoluble in water and easily reacts with air.
_____ 6. A burette is a long glass tube with a bulge in the middle.
_____7. A pipette is a long glass tube with a tap at the bottom.
_____8. Substances that have distinctly different colors in acidic and basic media are called analytes.
           9. pH scale is a system used to express the Hydroge-ion concentration of any substance.
____10. Salts are products formed when acid and base neutralize each other.
____11. Indicator is an ionic compound formed from the anion of an acid and cation of a base.
____12.The pOH of a solution is the negative logarithm of the hydrogen ion concentration.

II.                  PROBLEM SOLVING:  5 points each question; Show your solution. Use extra sheet .
A.      ACID-BASE TITRATION:
1.   In an acid-base titration, standard 0.35 M KOH is used to determine the unknown concentration of HCl solution.
                a. Write the  equation for the neutralization.
                b. If 40 mL of KOH solution was used to titrate 165 mL of HCl solution, calculate the
                    concentration of the acid.

2.    An acid-base titration, standard 0.1    M HNO3 is used to determine the concentration of an        unknown NaOH solution.
a. Write the  equation for the neutralization.
b. If 40 mL of HNO3 is required to neutralize 100 mL of NaOH, calculate the         concentration of the base.
                                3.   An acid-base titration reaches its end point when 300 mL of 0.20 M HCl is added to 45 mL of
      NaOH. What is the concentration of the NaOH?
B.      CALCULATING pH and pOH ( 5 pts. each)Express your answer in correct sig. fig.

1.       Given:  [ OH -] = 5.2 X 10 -9 M  . Calculate pOH, pH and [ H +]
2.       Given: pH = 4.06  Calculate [ OH -], pOH,  and [ H +]
3.       Find the pH and pOH of a 0.000 1 M HCl solution.
4.       If the [ OH -] is equal to 0.000 001 M, find the pH





Continuation…..
III.                IDENTIFICATION :
__________ 1. Homogeneous mixtures of ions, atoms, molecules of 2/more diff. substances.
__________ 2. Expresses the amount of solute in mole per kilogram of solvent.
__________ 3. Contains large amount of solute compared to the amount of solvent present.
__________ 4. Type of change if solution gives off energy to the environment.
__________ 5. Expresses the amount of solute in moles per liter of solution.
__________ 6. Number  of equivalent of solute per liter of solution.
__________ 7. Maximum amount of solute dissolved in a given amount of solvent.
__________ 8. Contains small amount of solute relative to the amount of solvent.
__________ 9. The ratio of the number of moles of solute in a given mole of solution.

IV.                Assign Oxidation Number (ON) on the following:
1.      HIO3                  H __, I __, O __
2.      NaMnO4               Na __, Mn __, O __
3.      SnO2                  Sn __, O __
4.      NOF                   N __, O __, F __
5.      NaO2                 Na __, O __

V.                 Classify each of the following ½ reactions as oxidation or reduction (2 points each)
1.      TiO2     →        Ti 3+                 __________
2.      Zn 2+                →        Zn        __________
3.      NH4 +   →        N2                    __________
4.      CH3OH →        CH2O               __________
5.      O2        →        O 2-                  __________

VI.               Complete the table
A.      Salt Hydrolysis
salt
Parent acid
Parent base
type of solution
       a.    MgF2
1
2
3
b.       KCl
4
5
6
c.       AlBr3
7
8
9
d.       CaSO4
10
11
12
e.       Ba3(PO4)2
13
14
15

B.      pH and pOH

[H +]
pH
[OH -]
pOH
Acidic or basic
1.
10 -6
a.
b.
c.
d.
2.
e.
12
f.
g.
h.
3.
i.
j.
10-3
k.
l.
4.
m.
n.
o.
7
p.
5.
q.
2
r.
s.
t.

f.        Name the following acids and bases:
1.       HCH3COO          2.NH4OH       3. HI              4. H3BO3       5. HF                   

g.       Write the formula of the following:

1.   Phosphorous acid                    2.  Nitric acid                           3. Hydrosulfuric acid                                               4.  Strontium hydroxide                                 5. Potassium hydroxide



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