U10 Keq and Le Chatelier's Principle

At what time does the reaction reach equilibrium?

• t₁
• t₂
• t₃
• t₄

An equilibrium constant with a large value, e.g. K_(eq) = 1000, indicates…

• A very fast reaction

• Mostly products at equilibrium

• Mostly reactants at equilibrium

• Nothing useful at all

What are [A] and [B]?

• concentration of reactants
• concentration of products
• energy of reactants
• energy of products

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-6

What is the equilibrium expression for:

Fe₃O₄(s) + 4H₂(g) <=> 3Fe(s) + 4H₂O(g)

K_(eq) =

• [Fe]³ [H₂O]⁴ / [Fe₃O₄] [H₂]⁴

• [Fe₃O₄] [H₂]⁴ / [Fe]³ [H₂O]⁴

• [H₂O]⁴ / [H₂]⁴

• [Fe] [H₂O] / [Fe₃O₄] [H₂]

Tags

NGSS.HS-PS1-6

If the equilibrium constant is much greater than one (K >> 1) then

• Equilibrium is not established.
• Equilibrium lies to the right (products are favored)
• Equilibrium lies to the left (reactants are favored)
• Neither products or reactants are favored.

Tags

NGSS.HS-PS1-6

If the equilibrium constant is much less than one (K << 1) then

• Equilibrium is not established.
• Equilibrium lies to the right (products are favored)
• Equilibrium lies to the left (reactants are favored)
• Neither products or reactants are favored.

Tags

NGSS.HS-PS1-6

N₂O₄(g) ↔ 2 NO₂(g)

What is the equilibrium constant expression?

• K_(eq) = [NO₂]²/[N₂O₄]

• K_(eq) = [N₂O₄]/[NO₂]²

• K_(eq) = [N₂O₄]²/[NO₂]

• K_(eq) = [NO₂]/[N₂O₄]²

Tags

NGSS.HS-PS1-6

A +  B <--> C + D   ΔH= 151kJ
Rewrite the above equation with energy as a reactant or product:

• A +  B <--> C + D + energy
• A +  B + energy <--> C + D 

Tags

NGSS.HS-PS1-4

If a system at equilibrium "shifts right"

• more products are made, reducing reactant concentrations

• more reactants are made, reducing product concentrations

• the reaction speeds up

• the reaction slows down

Tags

NGSS.HS-PS1-6

A reaction vessel with a capacity of 1.0 liter, in which the following reaction SO_{2 (g)} + NO_{2 (g)} <===> SO_{3 (g)} + NO (g) had reached a state of equilibrium, was found to contain 0.40 moles of SO₃ , 0.30 moles of NO, 0.15 moles of NO₂ , and 0.20 moles of SO₂. Calculate the equilibrium constant for this reaction.

• 0.25

• 1

• 4

• 6