Chem 2 Final

For a chemical reaction to be spontaneous only at high temperatures, which conditions must be met? A. Delta So > 0 ; Delta Ho > 0 B. Delta So > 0 ; Delta Ho < 0 C. Delta So < 0; Delta Ho < 0 D. Delta So < 0; Delta Ho > 0 E. Delta Go > 0

A

What is the conjugate base of sulfuric acid (H2SO4)? A. HSO4 B. H3O C. OH D. SO4 E. H3SO4

A

Which of the following compounds is miscible with water? A. CH3OH B. CH4 C. C6H6 D. CH3CH2OCH2CH3 E. None of the above

A

A 0.100 m solution of which compound would have the lowest freezing point? A. NaCl B. CaCl2 C. NaOH D. KI E. NaNO3

B

A compound crystallizes with cations (A) in a face centered cubic (fcc) lattice with 8 anions (X) within the unit cell. What is the formula of the compound? A. AX B. AX2 C. A2X D. A2X3 E. A7X2

B

At temperatures below 273K, it is observed that liquid water spontaneously freezes to form solid ice. What must be true about the entropy changes of the system and surroundings for this process? A. Delta S sys > 0 ; Delta S surr > 0 B. Delta S sys < 0 ; Delta S surr > 0 C. Delta S sys < 0; Delta S surr < 0 D. Delta S sys > 0; Delta S surr< 0 E. Delta S sys = 0 ; Delta S surr > 0

B

Below is a representation of the unit cell for nickel (II) oxide. How many O- anions are there in the unit cell? For anions, there are 8 corners, and 6 faces. For Ni cations, there are 12 edges. A. 1 B. 4 C. 8 D. 13 E. 14

B

If the enthalpy change is positive and the entropy change is negative, the reaction is A. spontaneous at all temperatures B. non-spontaneous at all temperatures C. spontaneous at low temperatures D. spontaneous at high temperatures E. none of the above

B

What is defined as a measure of the randomness or disorder of a system? A. Gibbs Free Energy B. Entropy C. Spontaneous Process D. Nonspontaneous Process E. Enthalpy

B

Which of the following physical properties will not be increased when a solute is added? A. Boiling Point B. Vapor Pressure C. Osmotic Pressure D. All of the above E. None of the above

B

For the following reaction at equilibrium, which choice gives a change that will shift the position of equilibrium to favor formation of more products? 2NOBr (g) <--> 2NO(g) + Br2 ; Delta H rxn = 30 kJ/mol A. decreasing the volume B. add more NO C. remove Br2 D. lower the temperature E. remove NOBr selectively

C

If a certain process has delta S univ > 0 at 25 C, the process may be described as A. exothermic B. endothermic C. spontaneous D. moving rapidly toward equilibrium E. violating the second law of thermodynamics

C

Which of the following properties indicates the presence of strong intermolecular forces in a liquid? A. a low heat of vaporization B. a low critical temperature C. a low vapor pressure D. a low boiling point E. a low melting point

C

Which of the following intermolecular forces is not electrostatic? A. L-D B. dipole-dipole C. H-bond D. none of the above E. all of the above

D

Which of the following liquids will have the highest vapor pressure at room temperature? The boiling point data for each liquid is given. A. water, 100 C B. Methanol, 65 C C. Ethanol, 78.5 C D. Diethyl ether, 34.5 C E. Ethylene Glycol, 198 C

D

Which of the following statements is true about the value of the equilibrium constant (Kc) for a reaction? A. it can be increased by increasing the concentration of a product B. it can be increased by decreasing the concentration of a reactant C. it can always be increased by increasing the volume of a system D. it can be changed by changing the temp E. none of the above

D

Which substance has London Dispersion forces? A. H2O 2. NH3 C. CH3CH2OH D. CH4 E. HCl

D

A spontaneous reaction always: A. Entropy (delta S rxn) is > 0 B. Entropy (delta S univ) is < 0 C. Entropy (delta S surr) is < 0 D. Gibbs Free Energy (delta G) is > 0 E. Gibbs Free Energy (delta G) is < 0.

E

True or False: Forming chemical bonds requires energy.

False

True or False: Gas A has a critical temperature of 250K and a critical pressure of 10 atm. It can still be liquified at 300K if the pressure is higher than 10atm.

False

True or False: The entropy change at 298K for the reaction NH4Cl (s) --> NH3 + HCl

False

True or False: A change in the temperature can change the value of the equilibrium constant

True

True or False: A temperature increase favors an endothermic reaction.

True