Question

How much energy is given off or absorbed when 26.0 mol of O 2 is reacted? CH4(g) + 2O2(g) --> CO2(g) + 2H2O(l) delta H = -890 kJ

Answer 1

The energy released when 26.0 mol of O2 is reacted in the combustion of methane is 11,570 kJ, based on the stoichiometric relationship that 1 mol of CH4 releases 890 kJ and the provided reaction requires 2 mol of O2 for every mol of CH4.

Step-by-step explanation:

To find out how much energy is given off when 26.0 mol of O2 is reacted based on the provided reaction equation, we can use stoichiometry and the given enthalpy change (ΔH). The balanced chemical equation CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) with a ΔH of -890 kJ informs us that the combustion of 1 mol of CH4 releases 890 kJ of heat energy. This is an exothermic reaction, indicating that energy is given off during the process.

To calculate the energy for 26.0 mol of O2, we need to consider the stoichiometry of the reaction. Since 2 mol of O2 are required for every 1 mol of CH4, reacting 26.0 mol of O2 would correspond to 13.0 mol of CH4. Hence, we would multiply the enthalpy change for 1 mol of CH4 by 13 to obtain the total energy for 26.0 mol of O2:

Energy = 13.0 mol CH4 × 890 kJ/mol = 11570 kJ

Thus, the reaction of 26.0 mol of O2 releases 11,570 kJ of energy.

Answer 2

Taking into account the definition of enthalpy of a chemical reaction, the quantity of heat released when 26 moles of O₂ are reacted is 11570 kJ.

The enthalpy of a chemical reaction as the heat absorbed or released in a chemical reaction when it occurs at constant pressure. That is, the heat of reaction is the energy that is released or absorbed when chemicals are transformed into a chemical reaction.

The enthalpy is an extensive property, that is, it depends on the amount of matter present.

In this case, the balanced reaction is:

CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g)

and the enthalpy reaction ∆H° has a value of -890 kJ.

This equation indicates that when 1 mole of CH₄ reacts with 2 moles of O₂, 890 kJ of heat is released.

When 26 moles of O₂ are reacted, then you can apply the following rule of three: if 2 moles of O₂ releases 890 kJ of heat, 26 moles of O₂ releases how much heat?

heat= (26 moles of O₂× 890 kJ)÷2 moles of O₂

heat= 11570 kJ

Finally, the quantity of heat released when 26 moles of O₂ are reacted is 11570 kJ.