What mass of iron must be in a hot pack to provide -335kj of heat when the iron reacts with oxygen and is converted to iron (111) oxide according to the following thermochemical equation? 2fe(s) + 1.5o2(g)—> fe2o3(s) delta h= -824.2kj/mol

48.1 grams.

Explanation

How many moles of the reaction is needed to provide that 335 kJ of heat?

ΔH = -824.2 kJ / mol according to the equation. In other words, each mole of the reaction releases 824.2 kJ of heat. (The value of ΔH is negative, which means that the reaction produces energy.) 335 / 842.2 = 0.4307 mol. It takes 0.4307 moles of the reaction shown in the equation to produce all the 335 kJ of heat.

How many moles of iron, Fe in 0.4307 moles of the reaction?

The coefficient in front of Fe in the equation is two. As a result, each mole of this reaction would consume two moles of Fe. The 0.4307 moles of the reaction will consume 2 × 0.4307 = 0.861 moles of Fe to produce 335 kJ of heat.

What's the mass of 0.8614 moles of iron, Fe?

Refer to a modern periodic table, the relative atomic mass of iron Fe is 55.85. As a result, the mass of one mole of iron Fe is 55.85 grams. 0.861 × 55.85 = 48.1 grams. Therefore, it takes 48.1 grams of iron to provide 335 kJ of heat through this reaction.

Yes you are correct use the scientific method