Exam 1
Which of the following statements is/are true?
a. C3H8 should have a lower melting point this C4H10.
b. H2O should have a higher viscosity than H2S.
c. SiF4 should have a higher boiling point than CF4.
d. CH3COOH should have a higher surface tension than CH3COCH3.
a-d
Which of the following statements is/are true?
a. The conjugate base of hydrogen carbonate is carbonate.
b. Dihydrogen phosphate is amphoteric.
c. In the reaction of sodium hydroxide with chloric acid, chloric acid and the chlorate ion are an acid-base conjugate pair.
d. A Bronsted-Lowry base is a proton acceptor; an Arrhenius base produces hydroxide in an aqueous solution.
a-d
Calculate the pH after 36.0 mL of 0.200 M KOH is added to 24.0 mL 0.300 HNO3.
7
Which of the following statements is/are true?
a. According to collision theory, reaction rate increases with increasing temperature.
b. According to collision theory, reaction rate increases with decreasing concentration.
c. For the reaction, 3A + 2B -> C + 4D, if the instantaneous rate is -0.060 M/s for A, then at the same moment the instantaneous rate would be -0.080 M/s for D.
d. Reaction rate generally increases with time.
a
This is what ATP stands for.
Which of the following statements is/are true?
a. If the solvent-solvent and solvent-solute interactions are weaker than the solute-solute interactions, a solution tends to form.
b. When two liquids form a homogenous mixture in any proportion, they are considered miscible.
c. Entropy is a measure of energy dispersal in a system; as energy spreads out in a system, entropy decreases.
d. Air is an example of a solution.
b, d
The exothermic reaction 2A(g) + B(l) ⇌ 3C(g) is initially at equilibrium. Which of the following statements is/are true given the stated disturbances?
a. If some B is added to the reaction vessel, the reaction will shift to the right.
b. If the volume of the reaction vessel if increased, the reaction will shift to the right.
c. If the reaction vessel is cooled, the reaction will shift to the right.
d. If some C is removed from the reaction vessel, the reaction will shift to the right.
e. If a catalyst is added, the reaction will shift to the right.
f. If an inert gas is added, the reaction will shift to the right.
b, c, d
Which of the following would make a buffer solution?
a. Adding 15 mL of 0.10 M NaOH to 15 mL of 0.10 M HCl
b. Adding 15 mL of 0.10 M NaNO3 to 15 mL of 0.10 M HNO3
c. Adding 15 mL of 0.10 M NH3 to 15 mL of 0.10 M HNO2
d. Adding 15 mL of 0.10 M HNO2 to 15 mL of 0.10 M KNO2
e. Adding 15 mL of 0.10 M HNO2 to 15 mL of 0.10 M KClO
f. Adding 15 mL of 0.10 M HClO to 15 mL of 0.10 M NaClO
g. Adding 15 mL of 0.10 M NH3 to 15 mL of 0.10 M KOH
d, f
Which of the following is/are true?
a. HBrO is a weaker acid than HIO
b. HBrO is a weaker acid than HBrO2
c. H2Se is a stronger acid than HsS
d. H2S is a stronger acid than HCl
e. Nitrite is a stronger base than nitrate
b, c, e
True or false: Saltwater has a higher boiling point than pure water.
True! (colligative properties- boiling point elevation)
The lattice energy of CaCl2 is -2247 kJ/mol and its enthalpy of hydration is -2293 kJ/mol. How much energy (in kJ) is released up dissolving 18.3 g of CaCl2 in water?
-7.58 kJ
DAILY DOUBLE: Calculate the entropy of vaporization in J/(mol*K) for H2O at its boiling point if the enthalpy of vaporization is 40.66 kJ/mol.
109 J/(mol*K)
A solution contains 0.450 M HA (weak acid, Ka = 4.10*10-9) and 0.240 M KA. Calculate the pH of this solution.
8.11
Which of the following statements is/are true?
a. The integrated rate law shows how rate depends on concentration; the differential rate law shows how concentration depends on time.
b. The differential rate law must be determined experimentally; the integrated rate law is derived from the differential rate law mathematically.
b
This nobel gas has an A as its first letter.
What is Argon?
Calculate the energy change (in kJ) to convert 50.0 g of water at 22.0 oC to ice at -54.0 oC. The enthalpy of fusion and enthalpy of vaporization of water are 6.02 kJ/mol and 40.7 kJ/mol, respectively. The heat capacity of water and ice are 4.18 and 2.09 J/(g*oC), respectively.
-26.9 kJ
DAILY DOUBLE: Calculate ΔGrxn in kJ at 45 oC for 2A(g) + B(l) ⇌ C(g) + 3D(g) if ΔGorxn = -12.5 kJ and the reaction vessel contains the following:
PA = 0.150 atm
nB = 5.00 mol
PC = 0.0500 atm
PD = 1.40 atm
-7.72 kJ
The activation energy of a reaction is 42.5 kJ/mol and the rate constant is 0.515 at 22.0 oC. What is the rate constant at 44.0 oC?
1.71
For the reaction B -> products, the half-life is measured to be 45.0 seconds when the initial concentration is 0.800 M. The reaction is first order in B. Calculate the concentration of B in M at 152 seconds.
0.0770 M
The only letter that doesn't appear in the periodic table.
What is the letter J?
Calculate the vapor pressure in psi (1 atm = 14.7 psi) of an aqueous 7.24 m potassium carbonate solution at 100.0 oC.
10.6 psi
The equilibrium constant for a certain reaction at 56 oC is 5.15. At what temperature in oC will the equilibrium constant be 12.5 if ΔHorxn = 16.8 kJ/mol?
112 oC
Calculate the pH at the equivalence point is 0.200 M KOH is used to titrate 24.0 mL of 0.300 M HNO2 (Ka = 4.50*10-4).
8.21
Calculate the mass in grams of sodium chloride that can be dissolved in 4.00 L solution with a Pb2+ concentration of 2.50*10-4 M before a precipitate will begin to form. Ksp for lead (II) chloride is 1.64*10-5.
59.9 g
In the Looney Tunes Cartoons, Wile E. Coyote often tries to blow up Road Runner with TNT. This is what TNT stands for.
What is trinitrotoluene?