Equilibrium

An equilibrium constant with a large magnitude indicates…

• A very fast reaction
• Higher concentration of products at equilibrium
• Higher concentration of reactants at equilibrium
• Nothing, without considering the stoichiometry of the reaction

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 reverse 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

When the rate of the forward reaction is equal to the rate of backward reaction, the system is said to be in

• Chemical Equilibrium
• Chemical Balance
• Stoichiometry
• Chemical Reaction

Tags

NGSS.HS-PS1-6

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

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

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

NGSS.HS-PS1-6

What is the proper K_eq for the following reaction? 
   2 NO_(g)  +  O_2(g) ⇌2 NO_2(g)

• K_eq = [NO₂]² / [NO]²[O₂]
• K_eq =  [NO]²[O₂] / [NO₂]²
• K_eq = [NO]²[O₂][NO₂]²
• K_eq = 2[NO][O₂] / 2[NO₂]

Tags

NGSS.HS-PS1-7

At what time (in seconds) is equilibrium established?

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

Tags

NGSS.HS-PS1-5

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-PS1-5

NGSS.HS-PS1-6