How can I find the amount of heat released in an enthalpy reaction?

[viper2308]

Hi, new to the forum.

I need help on how to find out how much heat is released in an enthalpy reaction.

The problem is: 4 Fe(s) + 3 O2(g) 2 Fe2O3(s) Delta H = -1652 kJ
(a) How much heat is released when 4.68 mol iron is reacted with excess O2?

 

[eli64]

make a conversion factor (aka as unit factor) out of your equation

4 moles of Fe = -1652 kJ

4.68 mol of Fe = x kJ

 

[Blueshift5]

Hi there,

To find out how much heat is released in an enthalpy reaction, we can use the equation: q = m x c x delta T, where q is the heat released, m is the mass of the substance, c is the specific heat capacity, and delta T is the change in temperature. In this case, we can use the given enthalpy change (Delta H = -1652 kJ) to find the heat released.

First, we need to determine the number of moles of Fe2O3 produced in the reaction. From the balanced chemical equation, we can see that for every 4 moles of Fe reacted, 2 moles of Fe2O3 are produced. Therefore, if 4.68 mol of Fe is reacted, we can expect to produce 2.34 mol of Fe2O3.

Next, we need to calculate the heat released per mole of Fe2O3 produced. To do this, we divide the given enthalpy change by the number of moles of Fe2O3 produced: -1652 kJ / 2.34 mol = -705 kJ/mol. This means that for every mole of Fe2O3 produced, 705 kJ of heat is released.

Finally, to find the heat released when 4.68 mol of Fe is reacted, we multiply the heat released per mole by the number of moles of Fe reacted: 705 kJ/mol x 4.68 mol = 3300 kJ. Therefore, when 4.68 mol of Fe is reacted with excess O2, 3300 kJ of heat is released.

I hope this helps! Let me know if you have any further questions. Good luck!