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
A beaker with a mixture of ice and water is maintained at equilibrium:
H2O(s) + heat <--> H2O(l)
If the temperature of the system is decreased:
Water freezes to form Ice (shift left)
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 compound should have the lowest boiling point and why?
1. CF4
2. CH2F2
3.CHF3
1- CF4
Which of the following will shift this reaction right
2NH3(g) + 3O2 (g) -> 2NO3 (s) + 3H2 (g)
Removing oxygen gas
Adding more NO3
Adding H2
Adding NH3 (g)
Adding NH3 gas
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)
Which of the following would be MOST soluble in water? Briefly explain your answer. • XeF2 • CH3(CH2)8CH2OH • CH3OH • CH3Cl • F2
CH3OH
"like dissolves like"
List the following in order of increasing standard molar entropy. Briefly explain your reasoning. Br2 (g), Br2 (l) , Fe(CO)5 (g), SCl3F3 (g)
Br2 (l) < Br2 (g) < SCl3F3 (g) < Fe(CO)5 (g)
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
. Classify the following solids as molecular, ionic, metallic, nonbonding atomic, or network covalent. a) I2 b) Xe c) Au
A- molecular
b- Nonbonding atomic
C- Metalic
If the endothermic reaction below is at equilibrium, give the direction equilibrium shifts for the following disturbance. C(s) + H2O(g) ⇌ CO(g) + H2(g)
Lowering the temperature
Shifts left
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
List the following compounds in order of increasing solubility in CCl4: 1. CH3OH 2. CH3CH2CH2OH 3. CH3CH2CH2CH2CH2CH3 4. CH3CH2OCH2CH3
1<2<4<3
Put the following in order of decreasing strength as an acid, given that Ka = 4.9 x 10−10 for HCN Ka = 4.6 x 10−4 for HNO2 Ka = 3.5 x 10−4 for HF
1. HNO3 2. HCN 3. HNO2 4. H2O 5. HF
1>3>5>2>4
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?