A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition and the way in which it is formed
Answer:
Anything not on the periodic table is an element non example! ... So, for a substance to be an element, all of its atoms must have the same number of protons. Examples of elements include hydrogen, lithium, nickel, and radium.
Explanation:
Answer:
ΔH°rxn = -47 kJ
Explanation:
Using Hess´s law for the reaction:
3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ,
the ΔH°rxn will be given by the expression:
ΔH°rxn kJ = 2ΔHºf(Fe3O4) + ΔHºf(CO2) - ( 3ΔHºf(Fe2O3) + ΔHºf(CO) )
= 2(-1118) + (-394) - ( 3( -824 ) + ( -111 ) )
= - 47 kJ
