When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation

The correct answer is Option 1.

Explanation:

We are given two intermediate equations and a final net equation for the formation of calcium carbonate. To form a net equation, we have to apply some operations on the second equation.

Two intermediate equations given are:

To get the final equation, we will half the second equation and reverse the equation, we get:

Equation 1:      

Equation 2:      

Net Equation:    

Hence, the correct answer is Option 1.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !