chem final (kill me)

Consider the following reaction at equilibrium. What effect will decreasing the temperature have on the system? CO2(g) + 2 H2O(l) ⇌ CH4(g) + 2 O2(g) ΔH° = +890 kJ At 175 K a) The reaction will shift to the left in the direction of reactants. b) The equilibrium constant will decrease. c) The equilibrium constant will increase. d) The reaction will shift to the right in the direction of products. e) No effect will be observed.

a

Define buffer capacity. A. Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness. B. Buffer capacity is the amount of acid that can be added until all of the base is used up. C. Buffer capacity is the amount of base that can be added until all of the acid is used up. D. Buffer capacity is the amount of acid that can be added until all of the acid is used up. E. Buffer capacity is the amount of base that can be added until all of the base is used up

a

Give the characteristic of a zero order reaction having only one reactant. a) The rate of the reaction is not proportional to the concentration of the reactant. b) The rate of the reaction is proportional to the square of the concentration of the reactant. c) The rate of the reaction is proportional to the square root of the concentration of the reactant. d) The rate of the reaction is proportional to the natural logarithm of the concentration of the reactant. e) The rate of the reaction is directly proportional to the concentration of the reactant.

a

Identify the change in state that does not have an increase in entropy. A catalyst can make a nonspontaneous process spontaneous. A. gasoline freezing B. water boiling C. ice melting D. dry ice subliming E. water evaporating

a

What element is being oxidized in the following redox reaction? Cr(OH)4−(aq) + ClO−(aq) → CrO42-(aq) + Cl−(aq) A. Cr B. O C. H D. Cl E. None of the above

a

Which of the following is NOT true? a) Hydrogen bonding is the strongest type of bond in a pure substance. b) The strongest intermolecular force present between two acetone molecules (CH3COCH3) is dipole-dipole forces. c) Dispersion forces occur in propanol, CH3CH2CH2OH. d) Hydrogen bonding occurs between methylamine molecules, CH3NH2. e) Dispersion forces are the only intermolecular force present between nonpolar molecules

a

Which of these neutralization reactions has a pH > 7 when equal moles of acid and base are mixed? A. CH3CO2H(aq) + NaOH(aq) ⇌ H2O(l) + NaCH3CO2(aq) B. H2SO4(aq) + 2 KOH(aq) ⇌2 H2O(l) + K2SO4(aq) C. HCl(aq) + NaOH(aq) ⇌ H2O(l) + NaCl(aq) D. HCl(aq) + C5H5N(aq) ⇌ C5H5NHCl(aq) E. None of the above

a

Which of the following is NOT true? A)Thermodynamics involves the relative chemical potentials of reactants and products. B)kinetics involves the rates of reactions and the energy of intermediate states. C)A spontaneous process occurs without ongoing outside intervention. D)A nonspontaneous process will not occur without external energy or being coupled with a highly spontaneous process. E)A catalyst can make a non spontaneous process spontaneous

e

Which of the following is true? a) In the process of dissolving a solute, the system reaches dynamic equilibrium when dissolution and recrystallization stop. b) In a saturated solution, the rate of recrystallization is greater than the rate of dissolution. c) The solubility of a solid is highly dependent on temperature and pressure. d) The Henry's law constant, kH, for a gas should increase with increasing temperature because the solubility of the gas increases. e) The formation of a solution will be favored if the solvent-solute interactions are stronger relative to solvent-solvent and solute-solute interactions.

e

breaks solute-solute and solvent-solvent interactions

endothermic

separation of solvent and solute molecules is --------

endothermic

to dissolve one substance in another, thus forming a solution, three things most occur

1. forces holding solute particles together must be broken 2. forces holding solvent particles together must be broken 3. attractions between solute and solvent particles must be formed.

is possible with only with certain hydrogen containing compounds

hydrogen bonds

a hydrogen atom requires a partial positive charge when it is covalently bonded to a --------

F atom

units for second-order reaction

M^-1s^-1

units for zero-order reaction

Ms^-1

hydrogen bonding occurs when a hydrogen atom is covalently bonded to (3)

N,O,F

Balance the following redox reaction. What are the coefficients in front of H2O and NO in the balanced reaction? Zn(s) + HNO3(aq) → Zn2+(aq) + NO(g) A. H2O =4, NO = 2 B. H2O =8, NO = 6 C. H2O =1, NO = 3 D. H2O =10, NO = 7 E. H2O =5, NO = 9

a

Choose the solvent below that would show the greatest boiling point elevation when used to make a 0.10 m nonelectrolyte solution. a) carbon tetrachloride, Kb = 5.03°C/m b). benzene, Kb = 2.53°C/m c).diethyl ether, Kb = 2.02°C/m d).water, Kb = 0.512°C/m e).acetic acid, Kb = 3.07°C/m

a

found in group 2

alkali earth metals

found on group 1

alkali metals

oxidation occurs at the -------

anode

In which of the following reactions will Kc = Kp? a) 4 NH3(g) + 3 O2(g) ⇌ 2 N2(g) + 6 H2O(g) b) SO3(g) + NO(g) ⇌ SO2(g) + NO2(g) c) 2 N2(g) + O2(g) ⇌ 2 N2O(g) d) 2 SO2(g) + O2(g) ⇌ 2 SO3(g) e) None of the above reactions have Kc = Kp.

b

Place the following in order of increasing acid strength. HBrO2 HBrO3 HBrO HClO3 a) HBrO2 < HClO3 < HBrO < HBrO3 b) HBrO < HBrO2 < HBrO3 < HClO3 c) HBrO2 < HBrO3 < HClO3 < HBrO d) HClO3 < HBrO2 < HBrO3 < HBrO e) HBrO < HClO3< HBrO3 < HBrO2

b

What is the overall order of the following reaction, given the rate law? NO(g) + O3(g) → NO2(g) + O2(g) Rate = k[NO][O3] a) 1st order b) 2nd order c) 3rd order d) 1 order e) 0th order

b

Which of the following is a Lewis base? a) AlCl3 b) H2O c) SiCl4 d) C5H12 e) None of the above are Lewis bases.

b

Which of the following best describes a reaction at equilibrium? a) Reactants are being consumed and products are being formed. b) The rate of the reaction is zero. c) The rates of the forward and reverse reactions are equal. d) Only products are present. e) The rate of the forward reaction is greater than the rate of the reverse reaction.

c

Which of the following is TRUE? a)A neutral solution contains [H2O] = [H3O+] b)A neutral solution does not contain any H3O+ or OH- c)An acidic solution has [H3O+] > [OH−] d)A basic solution does not contain H3O+ e)None of the above are true.

c

Which of the following is true, based on the reaction: 2 NO(g) + Br2(l) ⇌ 2 NOBr(g) a) Kp≠Kc b)𝐾p=P2 𝑁𝑂𝐵𝑟/P2NOBr2 c)𝐾p=P2𝑁𝑂𝐵𝑟/P2NO d)Kc=[𝑁𝑂𝐵𝑟] / [𝑁𝑂] e)Kc=[𝑁𝑂]2 / [𝑁𝑂𝐵𝑟]2

c

Which of the following is true? a) The stronger the intermolecular forces, the more likely it is that molecules are to evaporate at a given temperature, making the liquid more volatile. b) The rate of vaporization increases with decreasing surface area, temperature and intermolecular forces. c) Enthalpy of vaporization and enthalpy of fusion increase with increasing intermolecular forces. d) The substance with the highest enthalpy of vaporization between H2, CH3CH2OH, CH3OCH3, and CH3CH2CH3 is CH3OCH3. e) When the temperature of a liquid is decreased, the average thermal energy of the particles is increased relative to the strength of the intermolecular forces

c

Which of the following solutions is a good buffer system? A. A solution that is 0.10 M HBr and 0.10 M LiC2H3O2 B. A solution that is 0.10 M HI and 0.10 M NH4+ C. A solution that is 0.10 M HC2H3O2 and 0.10 M NaC2H3O2 D. A solution that is 0.10 M LiOH and 0.10 M KOH E. None of the above is buffer systems.

c

Which of the following statements is/are true? a) The surface tension of a liquid is the energy required to increase the surface area by a certain amount and therefore the surface tension is lower for substances with weaker intermolecular forces. b) Viscosity is resistance to flow and the viscosity at 20oC will be lower than the viscosity at 40oC as increased thermal energy will partially overcome the substance's intermolecular forces. c) Octane, CH3(CH2)6CH3, has a higher viscosity at 20oC than does pentane, CH3(CH2)3CH3. d) The rate of vaporization increases with increasing temperature, surface area, and intermolecular forces. e) All of the above are true.

c

Which one of the following statements is true? A. A buffer is an aqueous solution composed of two strong bases. B. A buffer can absorb an unlimited amount of base. C. A buffer resists pH change by neutralizing added acids and bases. D. A buffer does not change pH when strong base is added. E. All of the above are true.

c

Which reaction(s) is spontaneous? 1. Ni(s) + Zn2+(aq) → Ni2+(aq) + Zn(s) 2. Fe2+(aq) + Cd(s) → Fe(s) + Cd2+(aq) 3. Cr(s) + 3Ag+(aq) → Cr3+(aq) + 3 Ag(s) 4. Ni(s) + Pb2+(aq) → Ni2+(aq) + Pb(s) Eo data is below: Ag+(aq) + e− → Ag(s) Eo = 0.80 V Pb2+(aq) + 2e− → Pb(s) Eo = −0.13 V Ni2+(aq) + 2e− → Ni(s) Eo = −0.23 V Cd2+(aq)+2e-→Cd(s) Eo=-0.4V Fe2+(aq)+2e-→Fe(s) Eo=-.45V Cr3+(aq)+3e-→Cr(s) Eo+-.73V Zn2+(aq ) + 2e− → Zn(s) Eo=-.762V A)1 B)2 C)3 D)4 E)they are all spontaneous

c

releases the greatest amount of heat

condensation

Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br2 and OH− in the balanced reaction? Br2(l) → BrO3−(aq) + Br−(aq) A. Br2=1,OH− =2 B. Br2=2,OH− =5 C. Br2=3,OH− =3 D. Br2=3,OH− =6 E. Br2=1,OH− =6

d

Consider the following reaction at equilibrium. What effect will adding more SO3 have on the system? SO2(g) + NO2(g) ⇌ SO3(g) + NO(g) a) The reaction will shift in the direction of products. b) The reaction will shift to decrease the pressure. c) No change will occur since SO3 is not included in the equilibrium expression. d) The reaction will shift in the direction of reactants. e) The equilibrium constant will decrease.

d

Consider the following three-step mechanism for a reaction: Cl2(g) ⇌ 2Cl(g) Fast Cl(g)+CHCl3(g)→HCl(g)+CCl3(g) Slow Cl(g)+CCl3(g)→CCl4(g) Fast Which of the following statements is true? a) Cl2(g) and CCl3(g) are intermediates in this reaction. b) The first step of the mechanism is the rate-determining step c) The overall reaction for this mechanism is Cl2(g)+CHCl3(g) →HCl(g)+CCl3(g). d) The rate law for this proposed mechanism would be rate = k[Cl2]1/2 [CHCl3] e) None of the above is true.

d

Identify the strongest acid. a) H2O b) H2S c) H2Se d) H2Te

d

Place the following in order of DECREASING molar entropy at 298 K. HCl N2H4 He A. He>N2H4>HCl B. He>HCl>N2H4 C. N2H4>He>HCl D. N2H4>HCl>He E. HCl>N2H4>He

d

Which of the following compounds will be the most soluble in ethanol (CH3CH2OH)? a) Hexane (CH3CH2CH2CH2CH2CH3) b) Pentanol(CH3CH2CH2CH2CH2OH) c) Acetone (CH3COCH3) d) Ethylene glycol (HOCH2CH2OH) e) None of these compounds should be soluble in ethanol.

d

Which of the following statements is NOT TRUE? a) The average rate of a reaction decreases during a reaction. b) It is not possible to determine the rate of a reaction from its balanced equation. c) The rate of zero order reactions are not dependent on concentration. d) The half life of a first order reaction is dependent on the initial concentration of reactant. e) None of the statements are FALSE.

d

Which of the following statements is TRUE? a) A catalyst is a substance that increases the rate of a chemical reaction while being consumed in the reaction. b) A catalyst raises the activation energy of a reaction. c) Rate constants are not temperature dependent. d) An enzyme is a biological catalyst that increases the rates of biochemical reactions. e) None of the above are true.

d

Determine the cell notation for the redox reaction given below. 3 Cl2(g) + 2 Fe(s) → 6 Cl−(aq) + 2 Fe3+(aq) A. Cl2(g) ∣ Cl−(aq) ∣ Pt Fe(s) ∣ Fe3+(aq) B. Cl−(aq) ∣ Cl2(g) ∣ Pt Fe3+(aq) ∣ Fe(s) C. Fe3+(aq) ∣ Fe(s) Cl−(aq) ∣ Cl2(g) ∣ Pt D. Fe(s) ∣ Cl2(g) Fe3+(aq) ∣ Cl−(aq) ∣ Pt E. Fe(s) ∣ Fe3+(aq) Cl−(aq) ∣ Cl2(g) ∣ Pt

e

Identify the solute with the highest van't Hoff factor. a) nonelectrolyte b) KI c) MgSO4 d) CaCl2 e) AlCl3

e

What is the conjugate acid of HCO3− ? a) H3O+ b) H2O c) CO32- d) OH− e)H2CO3

e

a negitive change in ------ indicates that the products have a smaller number of available energy micro states than the reactants

entropy

a saturation solution rate of dissociation is ----- to the rate of crystallization

equal

form solute-solvent interactions

exothermic

a plot of the natural log of the concentration of the reactant versus time yields a straight line

frost-order

are found in group 17

halogens

dipole-dipole forces=

higher boiling point

higher molar mass=

higher boiling point

hydrogen bonding=

higher boiling point

are found in group 18

noble gases

a bike going up a hill is an example of a ----------reaction

nonspontaneous

what is the effective pH range of a buffer

pKa+-1

an exothermic reaction with a negative energy changes in ------- in the reverse direction of all temperatures

reverse

units for first order reaction

s^-1

the half life of the reaction gets shorter as the initial concentration is increased

second-order

interactions between the ions of sodium chloride, interactions involving ion-ion interactions

solute-solute

interactions formed between the sodium ions and the oxygen atoms of water molecules, interactions formed between the chloride ions and the hydrogen atoms of water molecules

solute-solvent

interactions between water molecules, involves dipole-dipole attractions

solvent-solvent

an endothermic reaction with a negative energy change is --------- in the reverse reaction

sontaneous

the spontaneity of a reaction is NOT necessarily related to the ------ of the reaction

speed

a ball rolling down hill is an example of a-------- reaction

spontaneous

a nonspontaneous reaction can be made spontaneous by coupling it to another process that is--------or by supplying energy from an-------- force.

spontaneous, external

as strength of intermolecular forces increases, ------ decreases

vapor pressure

the weaker the intermolecular forces, the more likely it is that molecules are to evaporate at a given temp, making the liquid more --------

volatile

the half life of the reaction is longer as the initial concentration is increased

zero-order