Which of these describes a Mole in Chemistry? A. A counting term for substances
B. The Molar mass of substance in grams
C. 6.02 x 10^23
D. All of the above describe a mole

D. All of the above describe a mole

Explanation:

Mole is the unit for amount of substance. It is used for describing large number of particles.

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number of particles.

For example: 1 mole of Na atom will weigh 23 grams and contains atoms.

Thus all the above describes a mole.

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.