DL Honors: Chemical Equilibrium and Keq

What are the two factors to look for when determining if the reaction is at equilibrium?

• Forward reaction rate is faster than the reverse and concentrations are equal
• Forward and reverse reaction rates are equal and concentration is constant
• Forward and revers reaction rates are equal and concentration is equal
• Forward reaction rate is faster than the reverse and concentration is equal

Tags

NGSS.HS-PS1-6

NGSS.HS-PS1-5

Which of the following is NOT true at equilibrium?

• The forward and reverse reactions proceed at the same rate.
• The concentrations of reactants and products do not change.
• The concentration of the reactants is equal to the concentration of the products.
• The forward and reverse reactions continue to occur.

Tags

NGSS.HS-PS1-6

An equilibrium constant with a large value, e.g. K_c = 1000, indicates…

• A very fast reaction
• Mostly products at equilibrium
• Mostly reactants at equilibrium
• Nothing useful at all

Tags

NGSS.HS-PS1-6

What are [A] and [B]?

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

Tags

NGSS.HS-PS1-6

NGSS.HS-PS1-5

What is the equilibrium expression for:
Fe₃O₄(s) + 4H₂(g) <=> 3Fe(s) + 4H₂O(g)
K_c =

• [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 concentration equilibrium constant expression?

• K_c = [NO₂]²/[N₂O₄]
• K_c = [N₂O₄]/[NO₂]²
• K_c = [N₂O₄]²/[NO₂]
• K_c = [NO₂]/[N₂O₄]²

Tags

NGSS.HS-PS1-6

At what time (in seconds) is equilibrium established?

• 0 seconds
• 1 second
• 5 seconds
• 10 seconds

Consider the following reaction. What would be the equilibrium constant expression?
4Br₂(g) + CH₄(g) ⇋  4HBr(g) + CBr₄(g)

• [Br₂]⁴  [CH₄]/ [HBr]⁴  [CBr₄]
• [HBr]⁴ [CBr₄]/ [Br₂]⁴ [CH₄]
• [HBr ]/ [Br₂]⁴ [CH₄]
• [HBr]⁴ [CBr₄]/ [Br₂]⁴ [CH]⁴