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| 1 |
Which statement describes a carbonated beverage at equilibrium (in a soft drink bottle)? |
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The contents are in a closed system and have constant macroscopic properties. |
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The contents are in a closed system and have variable macroscopic properties. |
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The contents are in an open system and have constant macroscopic properties. |
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The contents are in an open system and have variable macroscopic properties. |
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| 2 |
A student prepares a sugar solution by placing 100 g of solid sugar in a flask, adding 200 mL of distilled water, then placing a stopper in the flask and shaking the flask vigorously. A macroscopic property that indicates that the system is at equilibrium is that the
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rate of precipitation equals the rate of crystallizing |
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rate of dissolving equals the rate of crystallizing |
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amount of undissolved sugar gradually decreases |
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amount of undissolved sugar remains constant |
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| 3 |
The statement, "If a system is subjected to stress, the system acts to relieve the effects of the stress", is known as |
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the Arrhenius theory |
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the Brønsted-Lowry theory |
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the Lewis theory |
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Le Châtelier's principle |
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| 4 |
The hypothetical equilibrium reaction represented by the equation that follows.
BA(s) + 2 X(g)<---------> B(l) + X2A(g) + energy
This reaction can be shifted to increase the yield of products by adding |
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B(l) |
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X(g) |
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BA(s) |
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X2A(g) |
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| 5 |
Egg whites have an hydroxide ion concentration of 3.3 x 10–7 mol/L. The hydrogen ion concentration in egg whites is |
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3.3 x 107 mol/L |
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1.0 x 10-7 mol/L |
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6.7 x 10-8 mol/L |
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3.0 x 10-8 mol/L |
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| 6 |
A solution of sodium hydroxide was prepared for a chemical analysis using 0.65 g in 500 mL. The hydrogen ion concentration in the solution is
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3.3 x 10-2 mol/L |
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1.6 x 10-2 mol/L |
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3.1 x 10-13 mol/L |
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1.5 x 10-14 mol/L |
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| 7 |
A pH meter used to test a freshly opened carbonated soft drink gives a reading of 2.14, corresponding to a [H +(aq)] of |
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7.2 x 10-2 mol/L |
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3.1 x 10-3 mol/L |
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7.2 x 10-3 mol/L |
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3.1 x 10-5 mol/L |
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| 8 |
The following closed system is in dynamic equilibrium:
PCl5(g) <------> PCl3(g) + Cl2(g) delta-H = +169.9 kJ/mol
If the temperature of this system is increased at constant pressure, the changes in concentrations would be |
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[PCl5] increased, [PCl3] and [Cl2] decreased |
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[PCl5] and [Cl2] increased, [PCl3] decreased |
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[PCl3] and [Cl2] increased, [PCl5] decreased |
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[Cl2] increased, [PCl3] and [PCl5] decreased |
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| 9 |
For the following reaction the equilibrium concentrations at a given temperature are [NO(g)] = 1.0 mol/L, [O2(g)] = 6.0 mol/L, [NO2(g)] = 2.0 mol/L:
2NO(g) + O2(g) <-------> 2NO2(g)
The value of Keq for the system at this temperature is |
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0.33 |
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0.67 |
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1.5 |
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9.0 |
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| 10 |
The pH of a 4.0 x 10-2 mol/L monoprotic acid solution was measured and found to be 2.10. For this acid, the per cent dissociation with water is |
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0.79% |
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4.0% |
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20% |
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80% |
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