Chemical Equilibrium Constant

Which of the following is true about chemical reaction at equilibrium

• only the forward reaction stops

• only the reverse reaction stops

• both forward and reverse reactions stop

• the rate constants for the forward and reverse reactions are equal

• the rates of the forward and reverse reactions are equal

Tags

NGSS.HS-PS1-6

Which of the following is true regarding the concentration of the products, for a chemical reaction that is already at equilibrium, assuming no disruptions to the equilibrium?

• the concentrations of products will not change because there are no more products

• the concentrations of products will not change because the limiting reactant is gone

• the concentrations of products will not change because the forward and reverse rates are equal

• the concentrations of products will change continually because of reversibility

A chemical equilibrium may be established by starting a reaction with ____________

• reactants only

• products only

• equal quantities of reactants and products

• any quantities of reactants and products

• all of the above

If the reaction quotient Q has a smaller value than the related equilibrium constant, K, _________

• the reaction is at equilibrium

• the reaction is not at equilibrium, and will make more products at the expense of the reactants

• the reaction is not at equilibrium, and will make more reactants at the expense of the products

• the value of K will not increase until it is equal to Q

Tags

NGSS.HS-PS1-7

If the reaction quotient Q has a value larger than the related equilibrium constant, K _________

• the reaction is at equilibrium

• the reaction is not at equilibrium, and will make more products at the expense of reactants

• the reaction is not at equilibrium, and will make more reactants at the expense of products

• the value of K will increase until it is equal to Q

Which is the reactant - and why?

• A, as concentration decreases
• B, as concentration decreases
• A, as concentration increases
• B, as concentration increases

Tags

NGSS.HS-PS1-5

For the reaction...
SO₂ + O₂  <=>  SO₃
If the concentration of SO₂ is increased, the equilibrium position of the reaction will shift ___________.

• to the left
• to the right
• to the left and right 
• neither left nor right

Tags

NGSS.HS-PS1-5

What is the K_c expression for this reaction?
   2 NO_(g)  +  O_2(g) ⇌  2 NO_2(g)

• K_c = [NO₂]² / [NO]² [O₂]
• K_c =  [NO]² [O₂] / [NO₂]²
• K_c = [NO]² [O₂] [NO₂]²
• K_c = [NO₂]² / [NO]² +  [O₂]

What are [A] and [B]?

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

Tags

NGSS.HS-PS1-5

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 mol L^-1 SO₃ , and 0.30 mol L^-1 NO,
0.15 mol L^-1NO₂ , and 0.20 mol L^-1 SO₂.
Calculate the equilibrium constant  for this reaction. 

• 4
• .42
• .25
• 1

Tags

NGSS.HS-PS1-7