When iron metal reacts with sulfuric acid, it produces iron (III) sulfate and hydrogen gas. Balance the equation: Fe + H2SO4 → Fe2(SO4)3 + H2. Explain why it is necessary to balance chemical equations and why coefficients can be added to an equation, but subscripts cannot be changed.

2Fe + 3H₂SO₄ → Fe₂(SO₄)³ + 3H₂

It is necessary to balance chemical equations to obey the Law of Conservation of Matter.

Coefficients can be added to to show how many molecules are in a chemical. You can't change the subscripts because if you change the subscripts, you are changing the amounts of an element are in the chemical equation.

Explanation:

The numbers you use to balance the equation are 2,3,1, and 3.

LOCOMass(a.k.a-" The Law of Conservation of Matter") states that matter cannot be created or destroyed in any situation. If you have 12 atoms of a substance, you must get 12 back out. We balance the equations to make sure of that.

I already did the second question(it's basically an explanation within the answer itself).

Also, if you have trouble with balancing equations, I recomment making a small T chart of all your reactants and products of each element in an equation to better help understand what needs to be changed.

hope this helps!!

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles