Equilibrium and Equilibrium Expressions

Which is the correct equilibrium constant expression for the following reaction?

Fe₂O_3(s) + H_2(g) —> Fe_(s) + H₂O_(g)

• K = [H₂O]3 / [H₂]³

• K = [Fe₂O₃] [H₂]³ / [Fe]²[H₂O]³

• K = [Fe]²[H₂O]³ / [Fe_2O₃] [H₂]³

• K= [Fe] [H₂O] / [Fe₂O₃] [H₂]

• K = [H₂O] / [H₂]

Tags

NGSS.HS-PS1-6

The equilibrium constant expression for the reaction BrF_5(g) —> Br_2(g) + F_2(g) is

• Kc = [Br₂] [F₂] / [BrF_5]

• Kc = [BrF₅]² / [Br₂][F₂]⁵

• Kc = [Br₂] [F₂]⁵ / [BrF₅]²

• Kc = 2[BrF₅]² / ([Br₂] × 5[F₂]⁵)

• Kc = [Br₂] [F₂]² / [BrF₅]⁵

Tags

NGSS.HS-PS1-6

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science. CO_2(g) + H₂O_(l) —> H₂CO3(aq)

Which one of the following is the correct equilibrium constant expression (Kc) for this reaction?

• Kc= 1/ [H₂CO₃]

• Kc= [CO₂]/ [H₂CO₃]

• Kc= [H₂CO₃] / [CO₂]

• Kc= [CO₂] [H₂O] / [H₂CO₃]

• Kc= [H₂CO₃] / [CO₂] [H₂O]

Tags

NGSS.HS-PS1-6

Calculate Kc for the reaction HI_(g) —> H_2(g) + I_2(g) given that the concentrations of each species at equilibrium are as follows: [HI] = 0.85 mol/L, [I₂] = 0.60 mol/L, [H₂] = 0.27mol/L.

• 0.19

• 0.22

• 4.5

• 5.25

• 160

Tags

NGSS.HS-PS1-6

A chemical reaction in which products can react to re-form reactants is known as a(n)

• reforming reaction

• reversible reaction.

• buffered reaction

• stoichiometric reaction.

Tags

NGSS.HS-PS1-6

For any reaction at chemical equilibrium, the concentrations of products and reactants

• are equal.

• change

• remain unchanged

• decrease

Tags

NGSS.HS-PS1-6

A very high value for K indicates that

• reactants are favored.

• products are favored.

• equilibrium is reached slowly.

• equilibrium has been reached

Tags

NGSS.HS-PS1-6

This symbol indicates that a reaction is _____

• reversible

• irreversible

Tags

NGSS.HS-PS1-6

Around what time does the reaction reach equilibrium?

• 25 min

• 70 min

• 45 min

• 80 min

Tags

NGSS.HS-PS1-6

Changes in pressure will only affect substances that are in the ______ state.

• solid

• gas

• liquid