轉學考化學命題_200706
(附週期表)
(A) Please select and write the answers on the answer sheet: (60%) (5% each)
1. Which is not the correct chemical formula for the compound named?
a) potassium phosphate K3PO4
b) iron(II) oxide FeO
c) calcium carbonate CaCO3
d) sodium sulfide NaS
e) lithium nitrate LiNO3
2. Phosphorus has the molecular formula P4 and sulfur has the molecular formula S8. How
many grams of phosphorus contain the same number of molecules as 6.41 g of sulfur?
a) 3.10 g
b) 3.21 g
c) 6.19 g
d) 6.41 g
e) none of these
3. A mixture contained no fluorine compound except methyl fluoroacetate, FCH2COOCH3
(molar mass = 92.1 g/mol. When chemically treated, all the fluorine was converted to CaF2
(molar mass = 78.1 g/mol). The mass of CaF2 obtained was 12.1 g. Find the mass of
methyl fluoroacetate in the original mixture.
a) 92.0 g
b) 28.5 g
c) 24.2 g
d) 14.3 g
e) 12.1 g
4-5. Consider three 1.0-L flasks at STP. Flask A contains He gas, flask B contains O2 gas, and
flask C contains H2 gas.
4. In which flask do the gas particles have the lowest average kinetic energy?
a) flask A
b) flask B
c) flask C
d) all are the same
e) none
5. In which flask do the gas particles have the highest average velocity?
a) flask A
b) flask B
c) flask C
d) all are the same
e) none
6. For a neutral solution, it must be true that
a) pH = 7.00.
b) [H+] = 0 M.
c) [H+] = [OH-].
d) [H2O] = 1 x 10-14
e) At least two of the above.
7. A solution contains 0.450 M HA (Ka = 2.0 x 10-7) and 0.250 M NaA. Calculate the pH
after 0.050 mole of NaOH is added to 1.00 L of this solution.
a) 6.30
b) 6.44
c) 6.57
d) 6.70
e) none of these
8. A 100-mL sample of water is placed in a coffee cup calorimeter. When 1.0 g of an ionic
solid is added, the temperature decreases from 21.5°C to 20.8°C as the solid dissolves. For
the dissolving of the solid
a) H > 0
b) Suniv > 0
c) Ssys< 0
d) Ssurr > 0
e) none of these
9. Which of the following is a reasonable criticism of the Bohr model of the atom?
a) It makes no attempt to explain why the negative electron does not eventually fall into the
positive nucleus.
b) It does not adequately predict the line spectrum of hydrogen.
c) It does not adequately predict the ionization energy of the valence electron(s) for
elements other than hydrogen.
d) It does not adequately predict the ionization energy of the 1st energy level
electrons for one-electron species for elements other than hydrogen.
e) It shows the electrons to exist outside of the nucleus.
10. Which statement is correct?
a) H2O is linear.
b) The molecule ClO2 cannot be accurately described by a Lewis structure consistent with
the octet rule.
c) The diatomic molecule Cl2 is an example of a polar molecule.
d) The bonds in LiF have more covalent character than those in F2.
e) none of these
11. The hybridization of the central atom in ICl4- is:
a) sp
b) sp2
c) sp3
d) dsp3
e) d2sp3
12. The OH radical disproportionates according to the elementary chemical reaction
OH + OH Æ H2O + O. This reaction is second order in OH. The rate constant for the
reaction is 2.0 × 10-12 cm3/molecule×s at room temperature. If the initial OH
concentration is 1.0 ×1013 molecules/cm3, what is the first half-life for the reaction?
a) 20 s
b) 2.0 10–3 s
c) 0.050 s
d) 0.035 s
e) 12 s
(B) Please write your calculation process and answers on the answer sheet: (40%)
1. For the endothermic reaction, with Ni catalyst and at 750℃,
CH4(g) + H2O(g)
CO(g) + 3H2(g)
What will happen to a reaction mixture at equilibrium if
a. H2O(g) is removed?
b. The temperature is increased?
c. An inert gas is added?
d. CO(g) is removed?
e. The volume of the container is tripled?
2. Draw the titration cure of a generic weak acid HA with a strong base. Mark the points that
correspond to the following:
a. the equivalence point
b. the maximum buffering region
c. pH = pKa
d. pH depends only on [HA]
e. pH depends only on [A-]
f. pH depends only on the amount of excess strong base added.
3. Consider a sample containing 5.00 mol of a monatomic ideal gas that is taken from state
A to state B by the following two pathways:
Pathway one:
PA= 3.0atm, VA= 15.0L
Æ (1) Pc=3.00atm, Vc=55.0L
Æ (2) PB=6.00atm, VB=20.0L
Pathway two:
PA= 3.0atm, VA= 15.0L
Æ (1) PD=6.00atm, VD=15.0L
Æ (2) PB =6.00atm, VB =20.0L
For each step, assume that the external pressure is constant and equals the final pressure
of the gas for that step.
(a) Calculate q, w, △E and △H for each step, and calculate overall values for each
pathway. Please summary your results in a table.
(b) What is your conclusion comparing the results in (a).