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How much heat is absorbed/released when 25.00 g of NH3(g) reacts in the presence of excess O2(g) to produce NO(g) and H2O(l) according to the following chemical equation? 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(l) ΔH° = 1168 kJ

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428.7 kJ of heat are absorbed when 25.00 g of NH₃(g) reacts in the presence of excess O₂(g) to produce NO(g) and H₂O(l).

Let's consider the following thermochemical equation.

4 NH₃(g) + 5 O₂(g) → 4 NO(g) + 6 H₂O(l)  ΔH° = 1168 kJ

The standard enthalpy of the reaction is positive, which means that the reaction is endothermic, that is, heat is absorbed.

We will convert 25.00 g of NH₃ to moles using its molar mass (17.03 g/mol).

[tex]25.00 g \times \frac{1mol}{17.03g} = 1.468 mol[/tex]

1168 kJ of heat are absorbed when 4 moles of NH₃ react. The heat absorbed when 1.468 moles of NH₃ react is:

[tex]1.468 mol \times \frac{1168kJ}{4mol} = 428.7 kJ[/tex]

428.7 kJ of heat are absorbed when 25.00 g of NH₃(g) reacts in the presence of excess O₂(g) to produce NO(g) and H₂O(l).

Learn more: https://brainly.com/question/2874342

Chemical reactions are defined as the reaction in which two or more reactants combine to form single or more products. The heat can be absorbed or evolved in the reaction. The heat absorbed is 428.7kJ when ammonia reacts with excess oxygen.

Given that,

  • Mass of ammonia = 25 g
  • Molar mass of ammonia  = 17.03 g/mol

The chemical equation between ammonia and oxygen is:

  • [tex]\text {4 NH}_3 \;+\; \text {5 O}_2\;\rightarrow\; \text {4 NO + 6 H}_2\text {O}\;\;\;\;\;\Delta\text H&=1168 \text {kJ}[/tex]

Now, the enthalpy of the reaction is positive, such that the reaction is endothermic. In endothermic reaction heat is absorbed.

Now, converting the mass of ammonia into moles, we get:

  • [tex]25.00\text {g} \;\times\;\dfrac{1 \text{mol}}{17.03\text{g}} &= 1.468\; \text {mol}[/tex]

1168 kJ of heat is absorbed when 4 moles of ammonia react with oxygen. The heat absorbed in 1.468 moles, will be:

  • [tex]1.468\;\text{mol}\;\times\;\dfrac{1168\;\text{kJ}}{4\;\text{mol}}&=428.7\;\text{kJ}[/tex]

Therefore, when 25 grams of ammonia reacts in the presence of oxygen 428.7 kJ will be absorbed. Hence, it is an endothermic reaction.

To know more about heat energy, refer to the following link:

https://brainly.com/question/13988181?referrer=searchResults

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