Chemical Equilibrium Constant

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

At what time the reaction reached equilibrium?

• t₁
• t₂
• t₃
• t₄

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

NGSS.HS-PS1-6

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]

Consider the following reaction:
2SO_2(g) + O_2(g) <=> 2SO_3(g):  ΔΗ = - 197 kJ mol ^-1
Which of the following will NOT shift the equilibrium position to the right?

• Adding more O₂
• Adding a catalyst
• increasing the pressure
• Lowering the temperature

Given: 2A(g) <=> 2B(g) + C(g). At a particular temperature, K_c = 16000.
Raising the pressure, by decreasing the volume of the container, will...

• cause the value of K_c to increase
• cause the value of K_c to decrease
• have no effect on the value of K_c as temperature does not change
• favour the forward reaction

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

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

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]

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.