The reaction of Fe3O4(s) with hydrogen(g) to form iron(s) and water(g) proceeds as follows: Fe3O4(s) + 4 H2(g) 3 Fe(s) + 4 H2O(g) When 61.8 grams of Fe3O4(s) react with sufficient H2(g) , 40.3 kJ of energy are absorbed . What is the value of H for the chemical equation given?

 151 kJ

Explanation:

To calculate the moles :

It is given that:

0.267 moles of absorb energy = 40.3 kJ

Thus 1 mole of absorb energy =  

Thus the value of for the chemical equation given is 151 kJ

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.