Rates and Equilibrium

Given: 2A(g) <-> 2B(g) + C(g). At a particular temperature, K = 1.6x10⁴.
At a higher temperature, K = 1.8x10^-5. Placing the equilibrium mixture in an ice bath (thus lowering the temperature) will...

• cause [A] to increase
• cause [B] to increase
• gave no effect
• cannot be determined

Tags

NGSS.HS-PS1-5

Given: 2A(g) <-> 2B(g) + C(g). At a particular temperature, K = 1.6x10⁴.
Addition of chemical B to an equilibrium mixture of the above will...

• cause [A] to increase
• cause [C] to increase
• have no effect
• cannot be determined

Tags

NGSS.HS-PS1-5

Given: 2A(g) <-> 2B(g) + C(g). At a particular temperature, K = 1.6x10⁴.
If you mixed 5.0 mol B, 0.10 mol C, and 0.0010 mol A in a one-liter container, which direction would the reaction initially proceed?

• shift left
• shift right
• have no effect
• cannot be determined

Tags

NGSS.HS-PS1-5

Given: 2A(g) <-> 2B(g) + C(g). At a particular temperature, K = 1.6x10⁴.
Raising the pressure by lowering the volume of the container will...

• cause [A] to increase
• cause [B] to increase
• have no effect
• cannot be determined

Consider: 2H₂ + O₂ -> 2H₂O
What is the ratio of the initial appearance of water to the initial disappearance of oxygen?

• 1:1
• 2:1
• 1:2
• 2:2

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The rate of disappearance of ozone in the reaction 2O₃(g) -> 3O₂(g) is found to be 7.25x10^-3 atm over a certain time interval. What is the rate of appearance of O₂ during this interval? 

• 10.9x10^-3
• 7.25x10^-3
• 4.83x10^-3
• 17.5x10^-3

The decomposition of ozone may occur through the two-step mechanism shown:
step 1: O3 -> O₂ + O
step 2: O₃ + O -> 2 O₂
The oxygen atom is considered to be a(n)...

• reactant
• catalyst
• reaction intermediate
• activated complex

The experimental rate law for the decomposition of nitrous oxide (N₂O) to N₂ and O₂ is Rate = k[N₂O]². Two mechanisms are proposed: 
I.   N₂O -> N₂ + O
     N₂O + O -> N₂ + O₂
II.  2N₂O <-> N₄O₂
     N₄O₂ -> 2N₂ + O₂
Which of the following could be a correct mechanism?

• Mechanism I, with the first step as the rate-determining step
• Mechanism I, with the second step as the rate-determining step as long as the first step is a fast equilibrium step
• Mechanism II, with the second step as the rate-determining step if the first step is a fast equilibrium step
• None of the choices could be correct

Tags

NGSS.HS-PS1-5

The reaction of (CH₃)₃CBr with hydroxide ion proceeds:
(CH₃)₃CBr(aq) + OH^-(aq) -> (CH₃)₃COH(aq) + Br^-(aq)
What will the initial rate (in mol/L*s) be in Experiment 4?

• 0.003
• 0.006
• 0.009
• 0.018

Tags

NGSS.HS-PS1-5

Consider the following rate law: Rate = k[A]ⁿ[B]^m
How are the exponents n and m determined?

• by using balanced chemical equation
• By using the subscripts for the formulas
• By educated guess
• By experiment