Chemistry Equilibrium

This symbol indicates that a reaction is _____

• reversible

• irreversible

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

Which is the correct equilibrium constant expression for the following reaction? Fe₂O_3(s) + 3H_2(g) —> 2Fe_(s) + 3H₂O_(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 = [H₂] / [H₂O]

Tags

NGSS.HS-PS1-7

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]

Which of the following changes will shift the position of the equilibrium to the left?

• Increasing the temperature of an exothermic reaction.

• Increasing the pressure of a reaction that has the same number of moles of gas on both sides

• Adding a catalyst to a reaction

• Adding more concentrations to the reactants

Tags

NGSS.HS-PS1-6

At equilibrium, the rate of the forward reaction is ________ the rate of the backward reaction

• Greater than

• Equal to

• Less than

Tags

NGSS.HS-PS1-6

Which of the following will never affect the position of an equilibrium?

• The temperature

• The pressure

• A catalyst

• The concentration of reactants

Chemical equilibrium refers to the state of a system in which the concentration of the reactant and the concentration of the products do not change with time, and the system does not display any further change in properties. What is the principle related to chemical equilibrium?

• Mandeleev principle

• Arrhenius theory

• Le Chatelier

• Dalton principle

Hydrogen can be made by reacting carbon with steam:

C(s) + H₂O(g) ⇌ H₂(g) + CO(g)

How can the equilibrium concentration of hydrogen be increased?

• Increase the concentration of steam

• Increase the concentration of carbon monoxide

• Use less carbon in the reaction

• Increase the concentration of hydrogen

Tags

NGSS.HS-PS1-5

The thermal decomposition of calcium carbonate is reversible:

CaCO₃(s) ⇌ CaO(s) + CO₂(g)

What happens to the position of equilibrium when the pressure is increased?

• It does not change

• It moves to the left

• It moves to the right

• It stays constant