# How do you do mass to mass stoichiometry problems?

##### 1 Answer

I'm assuming you mean reacting masses - for example:

"Calculate the amount of

So first you need to write a balanced equation:

Then you need to divide the mass you are given by its molar mass, to find the number of moles that react, so..

Molar mass

Moles of

Then you need to multiply the number of moles of

Molar mass

Mass

If you have different stoichiometric ratios, it is simplest to multiply the molar mass by the coefficient first, so if you had a question, "Calculate the mass of

First write that balanced equation:

Then divide the moles of

Molar mass

Moles = 10 / (32 x 3) = 0.10417

Then multiply this number by the mass of

Molar mass

Mass