Answered

Discover a world of knowledge at Westonci.ca, where experts and enthusiasts come together to answer your questions. Join our platform to connect with experts ready to provide precise answers to your questions in various areas. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

We put 10.0 moles of [tex]$N_2O$[/tex] into a [tex]$2.00 \, dm^3$[/tex] container at some temperature where it decomposes according to
[tex]\[
2 N_2O_{(g)} \rightleftharpoons 2 N_2_{(s)} + O_2_{(s)}
\][/tex]

At equilibrium, 2.20 moles of [tex]$N_2O$[/tex] remain. Calculate the value of [tex]$K_c$[/tex] for the reaction.


Sagot :

Certainly! Let's work through this step-by-step to find the value of the equilibrium constant [tex]\( K_c \)[/tex] for the given reaction.

Given:
- Initial moles of [tex]\( N_2O \)[/tex]: 10.0 moles
- Volume of the container: [tex]\( 2.00 \, \text{dm}^3 \)[/tex]
- Moles of [tex]\( N_2O \)[/tex] remaining at equilibrium: 2.20 moles

The reaction is:
[tex]\[ 2 N_2O_{(g)} \rightleftharpoons 2 N_{2(g)} + O_{2(g)} \][/tex]

### Step 1: Calculate the change in moles of [tex]\( N_2O \)[/tex]

Initial moles of [tex]\( N_2O \)[/tex]: 10.0 moles

Equilibrium moles of [tex]\( N_2O \)[/tex]: 2.20 moles

Change in moles ([tex]\( \Delta N_2O \)[/tex]):
[tex]\[ \Delta N_2O = \text{Initial moles} - \text{Equilibrium moles} = 10.0 - 2.20 = 7.8 \, \text{moles} \][/tex]

### Step 2: Calculate moles of [tex]\( N_2 \)[/tex] and [tex]\( O_2 \)[/tex] produced

From the balanced reaction equation, we know that 2 moles of [tex]\( N_2O \)[/tex] decompose to produce 2 moles of [tex]\( N_2 \)[/tex] and 1 mole of [tex]\( O_2 \)[/tex].

Thus, moles of [tex]\( N_2 \)[/tex] produced ([tex]\( \Delta N_2 \)[/tex]) is equal to the change in moles of [tex]\( N_2O \)[/tex]:
[tex]\[ \Delta N_2 = 7.8 \, \text{moles} \][/tex]

Moles of [tex]\( O_2 \)[/tex] produced ([tex]\( \Delta O_2 \)[/tex]):
[tex]\[ \Delta O_2 = \frac{7.8}{2} = 3.9 \, \text{moles} \][/tex]

### Step 3: Calculate concentrations at equilibrium

The volume of the container is [tex]\( 2.00 \, \text{dm}^3 \)[/tex].

Concentration of [tex]\( N_2O \)[/tex] at equilibrium ([tex]\( [N_2O] \)[/tex]):
[tex]\[ [N_2O] = \frac{\text{Moles of } N_2O \text{ at equilibrium}}{\text{Volume}} = \frac{2.20}{2.00} = 1.1 \, \text{mol/dm}^3 \][/tex]

Concentration of [tex]\( N_2 \)[/tex] at equilibrium ([tex]\( [N_2] \)[/tex]):
[tex]\[ [N_2] = \frac{\Delta N_2}{\text{Volume}} = \frac{7.8}{2.00} = 3.9 \, \text{mol/dm}^3 \][/tex]

Concentration of [tex]\( O_2 \)[/tex] at equilibrium ([tex]\( [O_2] \)[/tex]):
[tex]\[ [O_2] = \frac{\Delta O_2}{\text{Volume}} = \frac{3.9}{2.00} = 1.95 \, \text{mol/dm}^3 \][/tex]

### Step 4: Write the expression for the equilibrium constant [tex]\( K_c \)[/tex]

The equilibrium constant [tex]\( K_c \)[/tex] for the reaction
[tex]\[ 2 N_2O_{(g)} \rightleftharpoons 2 N_{2(g)} + O_{2(g)} \][/tex]
is given by:
[tex]\[ K_c = \frac{[N_2]^2 [O_2]}{[N_2O]^2} \][/tex]

### Step 5: Substitute the equilibrium concentrations into the [tex]\( K_c \)[/tex] expression

[tex]\[ K_c = \frac{(3.9)^2 \times 1.95}{(1.1)^2} \][/tex]

### Step 6: Compute the value of [tex]\( K_c \)[/tex]

[tex]\[ K_c = \frac{15.21 \times 1.95}{1.21} \][/tex]

[tex]\[ K_c = \frac{29.6595}{1.21} \][/tex]

[tex]\[ K_c = 24.511983471074373 \][/tex]

Therefore, the equilibrium constant [tex]\( K_c \)[/tex] for the reaction is approximately 24.51.