How do I determine the value of the reaction

2HI(g) + 2.4 kcal --> H2(g) + i2(g)
delta H =
a) 2.4 kcal
b) -2.4 kcal
c) 0.00024 kcal
d) -0.00024 kcal

OK. You changed screen names BUT you also included units.

Then heat is added delta H is +. When heat is produced, delta H is -.
So for this _+2.4 kcal is delta H.

To determine the value of the reaction, you need to calculate the delta H (enthalpy change). The delta H is the difference in enthalpy between the products and the reactants of a reaction.

In this case, the given equation is:

2HI(g) + 2.4 kcal --> H2(g) + I2(g)

To calculate the delta H, you need to consider the enthalpy of the reactants and the enthalpy of the products. The enthalpy change can be determined by subtracting the enthalpy of the reactants from the enthalpy of the products.

First, you need to know the enthalpies of the reactants and products involved in the reaction. If these values are not provided, you will need to look them up in a reference book or a reliable source.

Once you have the enthalpies of the reactants and products, you can subtract the sum of the enthalpies of the reactants from the sum of the enthalpies of the products. The resulting value will be the delta H of the reaction.

In this case, the given reaction does not provide any enthalpy values for the reactants and products. Therefore, without additional information, it is not possible to determine the value of delta H.