CHM Test 2 Study

1/2 Life Rate Laws

([ ]0)/(2k)=t1/2 (ln(2))/k=t1/2 1/([ ]tk)=t1/2

Phosphorus forms two compounds with chlorine which are in equilibrium at 500 K according to the following equation PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) When 0.600 moles of PCl5 are introduced into a 1.00 L bulb at 500 K and it is found that after equilibrium is reached that the concentration of PCl5 is 0.0420 M. What is the equilibrium concentrations of Cl2?

0.558 M

Carbon monoxide gas reacts with hydrogen gas at elevated temperatures to form methanol. When 0.40 moles of CO and 0.30 moles of H2 are allowed to reach equilibrium in a 1.0L flask, and 0.030 moles of CH3OH, methanol, are formed. What is the value of KC?

1.4

When the following equation is balanced, the coefficient of AlCl3 is ________ . _ Al2O3 + _ C + _ Cl2 → _ AlCl3 + _ CO

2

Consider the following reaction: A(g) + 5/8B(g) ➛ C(g) + 3/4D(g) If [C] is increasing at the rate of 4.0 M/s, at what rate is [B] changing?

2.5 M/s

A 0.15 M solution of a weak acid is ionized 1.3%. What is its K value?

2.6x10^-5

When the following equation is balanced, the coefficient of H2O is ___. NH3 + H2O → NO2 + H2

4

At a given temperature a first-order reaction has a rate constant of 3.33×10-3 s-1. How much time is required for the reaction to be 75% complete?

420 s

The rate law for the reaction 3A ➛ 2B is rate = k[A]2 with a rate constant of 0.0447 L∙mol∙hr−1. What is the half-life of the reaction if the initial concentration of A is 0.500 M?

44.7 hr

Formic acid, which is a component of insect venom, has a Ka = 1.8 × 10-4. What is the concentration of hydronium ion in a solution that is initially 0.20M formic acid?

5.9x10^-3

Phosphorus forms two compounds with chlorine which are in equilibrium at 500 K according to the following equation PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) When 0.600 moles of PCl5 are introduced into a 1.00 L bulb at 500 K and it is found that after equilibrium is reached that the concentration of PCl5 is 0.0420 M. What is the equilibrium constant?

7.41

The decomposition of hydrogen peroxide in the presence of iodide ion is believed to occur via this mechanism.H2O2(aq) + I-(aq) → H2O(l) + IO-(aq)H2O2(aq) + IO-(aq) → H2O(l) + O2(g) + I-(aq) In this mechanism, I-(aq) is ___ .

A catalyst

Phosphorus forms two compounds with chlorine which are in equilibrium at 500 K according to the following equation PCl5(g) ⇌ PCl3 (g) + Cl2 (g) When 0.600 moles of PCl5 are introduced into a 1.00 L bulb at 500 K and it is found that after equilibrium is reached that the concentration of PCl5 is 0.0420 M.What is the equilibrium concentrations of PCl3? A: 0.558 M B: 0.279 M C: 14.3 M D: not enough information E: Something else

A: 0.558 M

Carbon monoxide gas reacts with hydrogen gas at elevated temperatures to form methanol. When 0.40 moles of CO and 0.30 moles of H2 are allowed to reach equilibrium in a 1.0L flask, and 0.030 moles of CH3OH, methanol, are formed. What is the value of KC? A: 1.4 B: 1.7 C: 0.83 D: 0.33 E: 0.30

A: 1.4

The coefficient of P4 (s) for the following reaction is: ___P4 (s) + ___S8 (s) ➞ ___P4S10 (s) A: 4 B: 3 C: 2 D: 1 E: 8

A: 4

The gas-phase reaction between A2 + B2 → 2AB, proceeds by bimolecular collision between A2 and B2 molecules. If the concentration of both A2 and B2 are doubles, then the reaction rate will change by a factor of ___ . A: 4 B: 2 C: 1 D: 1/2 E: 1/4

A: 4

Formic acid, which is a component of insect venom, has a Ka = 1.8 × 10-4. What is the concentration of hydronium ion in a solution that is initially 0.20M formic acid? A: 5.9 ×10-3 B: 5.9 ×10^3 C: 0.0060 D: 3.6 ×10^3 E: something else

A: 5.9 ×10-3

In a 0.050M solution of a weak monoprotic acid, HA, the concentration of hydronium ion is 1.8×10-3. The equilibrium constant, Ka, for the ionization of the acid is __________. A: 6.7×10-5 B: 1.6 ×10-7 C: 9.0×10-5 D: 3.6 × 10-2 E: 6.5 × 10-5

A: 6.7×10-5

The rate constant for a particular second-order reaction is 0.47 /(M×s). If the initial concentration of reactant is 0.25mol/L it takes __________ s for the concentration to decrease to 0.13mol/L A: 7.9 B: 1.4 C: 3.7 D: 1.7 E: 0.13

A: 7.9

A catalyst increase the rate of a reaction by.... A: Changing the mechanism of the reaction B: Increasing the activation energy of the reaction C: Increasing the concentration of one or more of the products D: Decreasing the difference in the relative energy of the reactants and products E: Increasing the energy of reactants

A: Changing the mechanism of the reaction

For the reaction 2C2H6 (g) + 7O2 (g) → 4CO2 (g) + 6H2O(l), the rate of disappearance of C2H6(g)... A: Is one-third the rate of disappearance of H2O(l). B: Is twice the rate of appearance of CO2(g). C: Equals the rate of disappearance of O2(g). D: Is seven times the rate of disappearance of O2(g)

A: Is one-third the rate of disappearance of H2O(l).

For the reaction of solid phosphorus, P4, reacting with chlorine gas to form phosphorus trichloride; what is the equilibrium expression? A: KEQ=[PCl3]4/[Cl2]6 B: KEQ=[PCl3]/[Cl2] C: KEQ=[PCl4]/[Cl2] D: KEQ=[PCl4]4/[Cl2]8 E: KEQ=[PCl4]4/[P4][Cl2]8

A: KEQ=[PCl3]4/[Cl2]6

Which species has the strongest oxygen-oxygen bond according to molecular orbital theory? A: O2+ B: O2- C: All Three are equivalent D: O2^2-

A: O2+

Which species has the strongest oxygen-oxygen bond according to molecular orbital theory? A: O2^+ B: O2^- C: All three are equivalent D: O2^2-

A: O2^+

A burning splint will burn more vigorously in pure oxygen than in air because... A: Oxygen is a reactant in combustion and the concentration of oxygen is higher in pure oxygen than it is in air. B: Oxygen is a product of combustion. C: Nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature. D: Nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion. E: Oxygen is a catalyst for combustion.

A: Oxygen is a reactant in combustion and the concentration of oxygen is higher in pure oxygen than it is in air.

A solution of sodium acetate in water is observed to become more basic as the temperature is raised. Which conclusion can be drawn? Equation of Reaction: C2HO21-(aq) + H2O(l) ⇌ HC2H3O2(aq) + OH1-(aq) A: The forward reaction proceeds with absorption of heat. B: The forward reaction proceeds with release of heat. C: Acetic acid is less soluble in hot water than cold water. D: At higher temperatures, Na+(aq) + OH1-(aq) → NaOH(s) will occur.

A: The forward reaction proceeds with absorption of heat.

A change in the temperature from 10°C to 20°C is found to double the rate of a particular reaction. How did the change in temperature affect the reacting molecules? A: The number of molecules above the reaction energy threshold doubled. B: The number of collisions per second doubled. C: The average energy of the molecules doubled. D: The average velocity of the molecules doubled. E: The activation energy of the molecules were doubled.

A: The number of molecules above the reaction energy threshold doubled.

For an endothermic reaction, what would be the effect if energy was added to the reactants? A: The rate of the reaction increases and the value of the equilibrium constant is unchanged. B: The rate of the reaction decreases and the value of the equilibrium constant increases. C: The rate of reaction increases and the value equilibrium constant decreases. D: Both the rate of reaction and equilibrium constant increases. E: The rate of reaction increases and the equilibrium constant increases.

A: The rate of the reaction increases and the value of the equilibrium constant is unchanged.

The concept of resonance describes molecular structures... A: Which have no suitable single lewis structure. B: Which have electron resonating. C: Which are formed from hybridized orbitals. D: Which have resonating structures. E: Which have several different geometrical arrangements.

A: Which have no suitable single lewis structure.

For the reaction 2C2H6 (g) + 7O2 (g) → 4CO2 (g) + 6H2O(l), the rate of disappearance of C2H6 (g) A: is one-third the rate of appearance of H2O(l). B: is twice the rate of appearance of CO2 (g). C: equals the rate of disappearance of O2 (g). D: is seven times the rate of disappearance of O2 (g).

A: is one-third the rate of appearance of H2O(l).

A ligand with a single donor atom is called __________. A: monodentate B: polydentate C: a chelon D: bidentate E: a chelate

A: monodentate

A ligand with a single donor atom is called.... A: monodentate B: polydentate C: a chelon D: bidentate E: a chelate

A: monodentate

A burning splint will burn more vigorously in pure oxygen than in air because... A: oxygen is a reactant in combustion and the concentration of oxygen is higher in pure oxygen than it is in air. B: oxygen is a product of combustion. C: nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature. D: nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion. E: oxygen is a catalyst for combustion.

A: oxygen is a reactant in combustion and the concentration of oxygen is higher in pure oxygen than it is in air.

What are the units of the rate constant for a first order reaction when the rate is expressed in mol•L-1•s-1? A: s^-1 B: L2•mol-2• s-1 C: L•mol-1 D: L•mol-1• s-1

A: s^-1

What are the units of the rate constant for a first order reaction when the rate is expressed in mol•L-1•s-1? A: s^-1 B: L^2•mol^-2• s^-1 C: L•mol^-1 D: L•mol^-1• s^-1

A: s^-1

The concept of resonance describes molecular structures . . . A: which have no suitable single Lewis structure. B: which have electron resonating. C: which are formed from hybridized orbitals. D: which have resonating structures. E: which have several different geometrical arrangements.

A: which have no suitable single Lewis structure.

For a first order reaction, the concentration decreases to 30% of its initial value in 5.0 min. What is the rate constant? A: 0.46 min-1 B: 0.24 min-1 C: 0.14 min-1 D: 0.060 min-1

B: 0.24 min-1

For the reaction; A → B, the rate law is rate = k[A]. If the reaction is 40.0% complete after 50.0 minutes, what is the value of the rate constant, k? A: 8.00x10^-3 min^-1 B: 1.02x10^-2 min^-1 C: 1.39x10^-2 min^-1 D: 1.83x10^-2 min^-1

B: 1.02x10^-2 min^-1

For the reaction; A → B, the rate law is rate = k[A]. If the reaction is 40.0% complete after 50.0 minutes, what is the value of the rate constant, k? A: 8.00×10-3 min-1 B: 1.02×10-2 min-1 C: 1.39×10-2 min-1 D: 1.83×10-2 min-1

B: 1.02×10-2 min-1

For the reaction of nitrogen gas and hydrogen gas forming ammonia gas, at a particular temperature, the equilibrium concentrations are 8.1 × 10-3M ammonia, 4.5 × 10-1M nitrogen, and 5.1 × 10-3M hydrogen gas. Calculate the Keq at this temperature. A: 3.5 B: 1.1 ×10^3 C: 1.1 ×10-3 D: 3.6 ×10-6 E: something else

B: 1.1 ×10^3

How many different isomers exist for the octahedral complex [Co(NH3)4Cl2]+? A: 1 B: 2 C: 3 D: 4

B: 2

How many different isomers exist for the octahedral complex [Co(NH3)4Cl2]+? A: 1 B: 2 C: 3 D: 4

B: 2

When the following equation is balanced, the coefficient of NH3 is __________. NH3 + H2O → NO2 + H2 A: 1 B: 2 C: 3 D: 4 E: 6

B: 2

Write the proper balanced equation for the following:Solid zinc sulfide and oxygen gas form solid zinc oxide and sulfur dioxide gas.What is the correct coefficients? A: 1,1,1,1 B: 2,3,2,2 C: 2,4,2,2 D: 1,2,1,1 E: 2,2,2,1

B: 2,3,2,2

When the following equation is balanced, the coefficients are __________. NH3 + H2O → NO2 + H2 A: 1,1,1,1 B: 2,4,2,7 C: 2,3,2,3 D: 1,2,1,5

B: 2,4,2,7

What is the coefficient of water when the following is properly balanced? _ C3H8O + _ O2 → _ CO2 + _ H2O A: 4 B: 8 C: 1 D: 2 E: 12

B: 8

The minimum energy needed to cause the reaction to occur. A: Transition state B: Activation energy C: Heat content D: Catalysis E: Net energy

B: Activation energy

In order to write the correct equilibrium, mass-action, expression for a reaction one must ______ . A: Have the calculated and measured equilibrium constant B: Have a properly balanced chemical equation C: Know the mechanism for the reaction D: Have values for the concentrations of the reactants E: Know the kinetic rate law for the reaction

B: Have a properly balanced chemical equation

For the reaction: SCN- (aq) + Fe(H2O)6+3 (aq) ⇌ H2O (l) + Fe(H2O)5SCN2+ (aq) , the reaction is exothermic predict what will happen to the equilibrium in terms of shifting Left, Right, or remaining the Same when some heat is added. A: Same B: Left C: Both Left and Right, it is equilibrium D: Right E: Uncertain, more information is needed

B: Left

Which substance in the reaction below either appears or disappears the faster? 4NH3+7O2→4NO2+6H2O A: NH3 B: O2 C: NO2 D: H2O E: All rates are the same

B: O2

For the reaction: SCN- (aq) + Fe(H2O)6+3 (aq) ⇌ H2O (l) + Fe(H2O)5SCN2+ (aq) , the reaction is exothermic predict what will happen to the equilibrium in terms of shifting Left, Right, or remaining the Same when some Fe3+ is added. A: Left B: Right C: Same D: Uncertain, more information is needed E: Both left and right, it is equilibrium

B: Right

For the reaction: SCN- (aq) + Fe(H2O)6+3 (aq) ⇌ H2O (l) + Fe(H2O)5SCN2+ (aq) , the reaction is exothermic predict what will happen to the equilibrium in terms of shifting Left, Right, or remaining the Same when more water is added. A: Shifts Left, because more water speeds up the reverse rate, and more reactants are being formed. B: Shifts Left, because water slows down the forward rate, and less products are being formed. C: Shifts Right, because water speeds up the forward rate, and more products are being formed. D: Shifts Right, because water slows down the reverse rate and less reactants are being formed. E: Remains the same, because water is the solvent and affects both the forward and reverse rates.

B: Shifts Left, because water slows down the forward rate, and less products are being formed.

For the reaction: SCN- (aq) + Fe(H2O)6+3 (aq) ⇌ H2O (l) + Fe(H2O)5SCN2+ (aq) , the reaction is exothermic predict what will happen to the equilibrium in terms of shifting Left, Right, or remaining the Same when more water is added. A: Shifts left, because more water speeds up the reverse rate, and more reactants are being formed. B: Shifts left, because water slows down the forward rate, and less products are being formed. C: Shifts right, because water speeds up the forward rate, and more products are being formed. D: Shifts right, because water slows down the reverse rate and less reactants are being formed. E: Remains the same, because water is the solvent and affects both the forward and reverse rates.

B: Shifts left, because water slows down the forward rate, and less products are being formed.

In order to write the correct equilibrium, mass-action, expression for a reaction one must ______ . A: have the calculated and measured equilibrium constant B: have a properly balanced chemical equation C: know the mechanism for the reaction D: have values for the concentrations of the reactants E: know the kinetic rate law for the reaction

B: have a properly balanced chemical equation

The reaction A → B + C obeys the rate law: rate=k[A]. Which graph will produce a straight line? A: [A] vs time B: ln[A] vs time C: 1/[A] vs time D: [A] vs 1/time

B: ln[A] vs time

The rate law for a certain reaction is found to be: rate = k [A] [B]2 How will the rate of this reaction compare if the concentration of A is doubled and the concentration of B is halved? The rate will

Be one-half the original rate

For the reaction A + B → C, the rate law is: Rate = k[A][B]2 . Which change(s) will increase the rate of the reaction? I Increasing the concentration of A II Increasing the concentration of B

Both I and II

This reaction is first order with respect to N2O5. 2N2O5(g) → 4NO2(g) + O2(g) If the half-life for this reaction is 19.0 minutes, what is the rate constant, k? A: 0.0526 min-1 B: 0.0263 min-1 C: 0.0365 min-1 D: 0.0158 min-1

C: 0.0365 min-1

This reaction is first order with respect to N2O5. 2N2O5(g) → 4NO2(g) + O2(g) If the half-life for this reaction is 19.0 minutes, what is the rate constant, k? A: 0.0158 min^-1 B: 0.0263 min^-1 C: 0.0365 min^-1 D: 0.0526 min^-1

C: 0.0365 min^-1

For the reaction NO2(g) + CO(g) → NO(g) + CO2(g) at temperatures below 500 K,the rate law is rate = k [NO2]2 . Which mechanism is consistent with this information? Mechanism 1: NO2 + NO2 → NO3 + NO slow CO + NO3 → CO2 + NO2 fast Mechanism 2: NO2 + NO2 → NO3 + NO fast CO + NO3 → CO2 + NO2 slow A: 2 only B: neither 1 nor 2 C: 1 only D: either 1 or 2

C: 1 only

Write the proper balanced equation for the following: Solid zinc sulfide and oxygen gas form solid zinc oxide and sulfur dioxide gas. What is the correct coefficients? A: 1, 1, 1, 1 B: 1, 2, 1, 1 C: 2, 3, 2, 2 D: 2, 2, 2, 1 E: None of the choices given

C: 2, 3, 2, 2

Write the proper balanced equation for the following:Solid zinc sulfide and oxygen gas form solid zinc oxide and sulfur dioxide gas.What is the correct coefficients? A: 1,1,1,1 B: 1,2,1,1 C: 2,3,2,2 D: 2,2,2,1 E: none of the choices given

C: 2,3,2,2

A 0.15 M solution of a weak acid is ionized 1.3%. What is its K value? A: 1.1 ×10-3 B: 2.0 ×10-3 C: 2.6 ×10-5 D: 1.3 ×10-2

C: 2.6 ×10-5

When the following equation is balanced, the coefficient of H2is __________. _ Al + _ H2O → _ Al(OH)3 + _ H2 A: 1 B: 2 C: 3 D: 4 E: 6

C: 3

Catalysts speedup a reaction by... A: Increasing the energy of the reactants. B: Lowering the reaction's required energy. C: Allowing an alternate pathway of lower energy. D: Heating the reaction. E: Reducing the steps required.

C: Allowing an alternate pathway of lower energy.

Xenon tetrafluoride, XeF4, can be prepared by heating Xe and F2 together. What is the equilibrium expression for this reaction? A: KC=[XeF4]/[Xe][F2] B: KC=[XeF4]/2[Xe][F2] C: KC=[XeF4]/[Xe][F2]2 D: Kc=[Xe][F2]/[XeF4] E: KC=[Xe][F2]2/[XeF4]

C: KC=[XeF4]/[Xe][F2]2

For an endothermic reaction, what would be the effect if energy was added to the reactants? A: Both the rate of reaction and equilibrium constant increases. B: The rate of reaction increases and the value equilibrium constant decreases. C: The rate of the reaction increases and the value of the equilibrium constant is unchanged. D: The rate of the reaction decreases and the value of the equilibrium constant increases E: The rate of reaction increases and the equilibrium constant increases.

C: The rate of the reaction increases and the value of the equilibrium constant is unchanged.

If the rate law for the reaction 2A + 3B → products is first order in A and second order in B, then the rate law is rate = _________ . A: k[A][B] B: k[A]2[B]3 C: k[A][B]2 D: k[A]2[B] E: k[A]2[B]2

C: k[A][B]2

The following reaction occurs in aqueous solution: NH4+(aq) + NO2-(aq) → N2(g) + 2 H2O(l) The data below is obtained at 25°C. NH4+(mol/L) NO2-(mol/L) . . Inital 0.0100 . . 0.200 . . . . 3.2×10^-3 0.0200 . . . . . 0.200 . . . . . . . . 6.4×10-3 The order of the reaction in NH4+ is __________. A: -2 B: -1 C: +2 D: +1 E: 0

D: +1

A solution of 8.0M of a weak acid, HA, is 0.47% ionized. What is the Ka of the weak acid? A: 3.8 B: 0.038 C: 0.0014 D: 0.00018 E: something else

D: 0.00018

Metallic sodium has a body-centered cubic unit cell. How many atoms are contained in one unit cell? A: 5 B: 1 C: 9 D: 2

D: 2

Write the proper balanced equation for the following:Ammonia gas reacts with oxygen gas to form nitrogen dioxide gas and water vapor.What is the correct coefficient for ammonia gas? A: 1 B: 2 C: 3 D: 4 E: None of the above

D: 4

Write the proper balanced equation for the following:Ammonia gas reacts with oxygen gas to form nitrogen dioxide gas and water vapor.What is the correct coefficient for ammonia gas? A: 1 B: 2 C: 3 D: 4 E: none of the choices given

D: 4

Write the proper balanced equation for the following:Ammonia gas reacts with oxygen gas to form nitrogen dioxide gas and water vapor.What is the correct coefficients? A: 1,1,1,1 B: 1,2,1,3 C: 2,2,2,3 D: 4,7,4,6 E: 4,10,4,6

D: 4,7,4,6

The reaction, CH3-N≡C → CH3-C≡N, is a first-order reaction. At 230.0°C, k=6.29×10-4s-1 If [CH3-N≡C] is 1.00×10-3M initially, [CH3-N≡C] is __________ after 1.000×103s. A: 1.00×10-6 B: 2.34×10-4 C: 4.27times;10-3 D: 5.35×10-4 E:1.88×10-3

D: 5.35×10-4

The reaction CH3-N≡C → CH3-C≡N is a first-order reaction. At 230.3°C,k=6.29×10-4s-1 If [CH3-N≡C] is 1.00×10-3M initially, [CH3-N≡C] is __________ after 1.000×103s A: 1.00×10^-6 B: 2.34×10^-4 C: 4.27times;10^-3 D: 5.35×10^-4 E: 1.88×10^-3

D: 5.35×10^-4

A reaction was found to be second order in carbon monoxide concentration. The rate of the reaction __________ if the [CO] is doubled, with everything else kept the same. A: Increases by a factor of two B: Remains unchanged C: Increases by a factor of three D: Increases by a factor of four E: Decreases by a factor of two

D: Increases by a factor of four

When the following equation is balanced, the coefficient of CaO is ________ . _ CaO(s) + _ H3O+(aq) → _ Ca2+(aq) + _ H2O(l) A: 5 B: 4 C: 2 D: 3 E: 1

E: 1

Combustion of aspirin (C7H6O3) with air (O2) produces carbon dioxide and water vapor. The sum of the coefficients of this balanced equation is: A: 15 B: 17 C: 16 D: 14 E: 18

E: 18

Write the proper balanced equation for the following:Ammonia gas reacts with oxygen gas to form nitrogen dioxide gas and water vapor.What is the correct coefficient for oxygen gas? A: 1 B: 2 C: 3 D: 5 E: 7

E: 7

The decomposition of hydrogen peroxide in the presence of iodide ion is believed to occur via this mechanism. H2O2(aq) + I-(aq) → H2O(l) + IO-(aq) H2O2(aq) + IO-(aq) → H2O(l) + O2(g) + I-(aq) In this mechanism, I-(aq) is ___ . A: Spectator B: A reactant C: The activated complex D: A product E: A catalyst

E: A catalyst

In which reaction would an increase in pressure at constant temperature have no effect on the relative amounts of the substances present in the equilibrium mixture? A: 2 CO(g) + O2(g) → 2 CO2(g) + Heat B: N2(g) + 3H2(g) → 2 NH3(g) + Heat C: All reaction would have no effect. D: 2 NO(g) + O2(g) → 2 NO(g) + Heat E: Heat + N2(g) + O2(g) → 2 NO(g)

E: Heat + N2(g) + O2(g) → 2 NO(g)

Even if it is present at the beginning of a reaction, its concentration increases as the reaction proceeds. A: Reactant B: Activated Complex C: Intermediate D: Catalyst E: Product

E: Product

The decomposition of hydrogen peroxide in the presence of iodide ion is believed to occur via this mechanism.H2O2(aq) + I-(aq) → H2O(l) + IO-(aq)H2O2(aq) + IO-(aq) → H2O(l) + O2(g) + I-(aq) In this mechanism, I-(aq) is ___ . A: spectator B: a reactant C: the activated complex D: a product E: a catalyst

E: a catalyst

In the equilibrium 1 H2 (g) + 1 I2 (g) ⇌ 2 HI (g) , an initial mixture contains 1 mol of H2 and 3 mol I2. Which of the following is the amount of HI expected at equilibrium? A: less than 4 mol B: 1 mol C: 2 mol D: more than 2 but less than 4 mol E: less than 2 mol

E: less than 2 mol

Rate=k[ ]^1 ln[ ]t=ln[ ]0-kt (ln(2))/k=t1/2

First Order

Xenon tetrafluoride, XeF4, can be prepared by heating Xe and F2 together. What is the equilibrium expression for this reaction?

Kc=[XeF4]/([Xe][F2}^2)

Ammonia

NH3

Differential Rate Laws

Rate=-k Rate=k[ ]^1 Rate=-k[ ]^2

For the reaction: SCN- (aq) + Fe(H2O)6+3 (aq) ⇌ H2O (l) + Fe(H2O)5SCN2+ (aq) , the reaction is exothermic predict what will happen to the equilibrium in terms of shifting Left, Right, or remaining the Same when some Fe3+ is added.

Right

Rate=-k[ ]^2 1/([ ]t)=1/([ ]0)+kt 1/([ ]tk)=t1/2

Second Order

For an endothermic reaction, what would be the effect if energy was added to the reactants?

The rate of the reaction increases and the value of the equilibrium constant is unchanged.

Half Life is..

The time required for half the concentration of a reactant to disappear.

Consider this reaction. 2H2(g) + 2NO(g) → N2(g) + 2H2O(g) The rate law for this reaction is rate = k [H2] [NO]2 . Under what conditions could these steps represent the mechanism? Step 1. 2NO = N2O2 Step 2. N2O2 + H2 → N2O + H2O Step 3. N2O + H2 → N2 + H2O

These steps could be a mechanism if step 2 is the slow step.

Rate=-k [ ]t=[ ]0-kt ([ ]0)/(2k)=t1/2

Zero Order

Initial Rate Laws

[ ]t=[ ]0-kt ln[ ]t=ln[ ]0-kt 1/([ ]t)=1/([ ]0)+kt

A reaction was found to be second order in carbon monoxide concentration. The rate of the reaction __________ if the [CO] is doubled, with everything else kept the same.

increases by a factor of four

Arrhenius Equation

ln(k2/k1)=-H/R(1/T1-1/T2)

Half-life is

the time required for half the concentration of a reactant to disappear.