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The enthalpies of formation of N(2)O and...

The enthalpies of formation of `N_(2)O` and `NO` are respectively `82` and `90 kJ mol^(-1)`. The enthalpy of reaction
`2N_(2)O(g)+O_(2)(g)to4NO(g)` is

A

`8 kJ`

B

`88 kJ`

C

`-16 kJ`

D

`196 kJ`

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The correct Answer is:
To find the enthalpy of the reaction \(2N_2O(g) + O_2(g) \rightarrow 4NO(g)\), we will use the enthalpies of formation of \(N_2O\) and \(NO\) provided in the question. ### Step 1: Write the formation reactions The formation reaction for \(N_2O\) is: \[ N_2(g) + \frac{1}{2}O_2(g) \rightarrow N_2O(g) \quad \Delta H_f = 82 \, \text{kJ/mol} \] The formation reaction for \(NO\) is: \[ \frac{1}{2}N_2(g) + \frac{1}{2}O_2(g) \rightarrow NO(g) \quad \Delta H_f = 90 \, \text{kJ/mol} \] ### Step 2: Adjust the formation reactions To find the enthalpy of the target reaction, we need to manipulate these formation reactions. 1. Multiply the formation reaction of \(N_2O\) by 2: \[ 2N_2(g) + O_2(g) \rightarrow 2N_2O(g) \quad \Delta H = 2 \times 82 \, \text{kJ} = 164 \, \text{kJ} \] 2. Multiply the formation reaction of \(NO\) by 4: \[ 2N_2(g) + 2O_2(g) \rightarrow 4NO(g) \quad \Delta H = 4 \times 90 \, \text{kJ} = 360 \, \text{kJ} \] ### Step 3: Write the overall reaction Now, we can write the overall reaction using the adjusted formation reactions: - From the first reaction, we have \(2N_2O(g)\) on the left. - From the second reaction, we have \(4NO(g)\) on the right. ### Step 4: Subtract the reactions Now we subtract the first reaction from the second: \[ (2N_2(g) + 2O_2(g) \rightarrow 4NO(g)) - (2N_2(g) + O_2(g) \rightarrow 2N_2O(g)) \] This gives: \[ O_2(g) + 2N_2O(g) \rightarrow 4NO(g) \] ### Step 5: Calculate the enthalpy change The enthalpy change for the overall reaction is: \[ \Delta H = 360 \, \text{kJ} - 164 \, \text{kJ} = 196 \, \text{kJ} \] ### Step 6: Adjust the sign Since we are looking for the enthalpy of the reaction \(2N_2O(g) + O_2(g) \rightarrow 4NO(g)\), we need to reverse the sign: \[ \Delta H = -196 \, \text{kJ} \] ### Final Answer Thus, the enthalpy of the reaction \(2N_2O(g) + O_2(g) \rightarrow 4NO(g)\) is: \[ \Delta H = -196 \, \text{kJ} \] ---

To find the enthalpy of the reaction \(2N_2O(g) + O_2(g) \rightarrow 4NO(g)\), we will use the enthalpies of formation of \(N_2O\) and \(NO\) provided in the question. ### Step 1: Write the formation reactions The formation reaction for \(N_2O\) is: \[ N_2(g) + \frac{1}{2}O_2(g) \rightarrow N_2O(g) \quad \Delta H_f = 82 \, \text{kJ/mol} \] ...
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DINESH PUBLICATION-CHEMICAL THERMODYNAMICS AND CHEMICAL ENERGETICS -Exercise
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  2. Which of the following value of DeltaH(f)^(@) represent that the produ...

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  19. Which of the following is true for a reaction H(2)O(l)toH(2)O(g) at 10...

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