Determine the amount of heat (in kJ) given off when 1.26 × 104 g of ammonia are produced according to the equation N2(g) + 3H2(g) ⟶ 2NH3(g) ΔH°rxn = −92.6 kJ/mol Assume that the reaction takes place under standardstate conditions at 25°C.

Respuesta :

Answer: The enthalpy of the reaction for given amount of ammonia will be -3431.3 kJ.

Explanation:

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]  

For ammonia:

Given mass of ammonia = [tex]1.26\times 10^4g=1260g[/tex]

Molar mass of ammonia = 17 g/mol

Putting values in above equation, we get:

[tex]\text{Moles of ammonia}=\frac{1260g}{17g/mol}=74.11mol[/tex]

We are given:

Moles of ammonia = 74.11 moles

For the given chemical reaction:

[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g);\Delta H^o_{rxn}=-92.6kJ[/tex]

By Stoichiometry of the reaction:

If 2 moles of ammonia produces -92.6 kJ of energy.

Then, 74.11 moles of ammonia will produce = [tex]\frac{-92.6kJ}{2mol}\times 74.11mol=-3431.3kJ[/tex] of energy.

Thus, the enthalpy of the reaction for given amount of ammonia will be -3431.3 kJ.

Answer:

-34317.56 Kj

Explanation:

  • Moles of ammonia = mass/molar mass

=1.26 x 10^4/17

= 741.2 moles

If 2 moles of ammonia gives - 92.6 Kj/mol

What about 741.2 moles

741.2/2 x - 92.6

= - 34317.56 KJ

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