# How to solve stoichiometry problems step by step using 7 steps

Solving stoichiometry problems by steps always involves a proper understanding of what is required, and the techniques needed in tackling stoichiometry calculations.

First, you need to understand that stoichiometry is the branch of chemistry that deals with the calculation of the amounts of reactants and products involved in a balanced chemical equation

There are seven step-by-step guides on how to solve stoichiometry calculations that I will show you to ease the stress of students on stoichiometry problems.

## Step 1: Be able to write a balanced chemical equation:

The first step in solving stoichiometry problems is being able to Write and balance chemical equation for the reaction and make sure it is balanced, which means that the number of atoms of each element is the same on both sides of the equation.

If you are unable to balance chemical equations, then you may struggle in solving stoichiometry problems because that is the first step in solving stoichiometry calculations.

Example

Mg + HCl ====MgCl2 + H2

The equation is not balanced, so you need to balance it first, so I will just show how to balance it though I have given full detail post on how to balance chemical equations.

Mg + HCl ====MgCl2 + H2

1Mg + 1H 1Cl =====1 Mg 2Cl + 2H

So we balance the equations

Mg + 2HCl ====MgCl2 + H2

## Step 2: Determine the given amount and unknown amount of substance from given information

The second step is to determine what information is given in the problem and the information required to solve the problem. This could be the mass of a reactant or product, the volume of a gas, or the number of moles of a substance and the compare bit to the required amount of substance.

It is important to recall that it is the given information that is needed in tackling the required problem because it is the known data.

Example

What mass of magnesium chloride would be produced by reacting 2.5 moles of magnesium with hydrochloric acid?

Solution

Mg + HCl ====MgCl2 + H2

So, the given information is moles of Magnesium while the unknown mass is magnesium chloride.

## Step 3: Convert the given information to moles

Then you compare the given substance to the unknown or required substance using mole ratio. You can also alternatively convert masses to mole using the mole to mass stoichiometry conversion factor. Afterwards, you can easily use the mole ratio to solve the molar mass of the substance by converting the given information to moles. The molar mass is the mass of one mole of a substance and can be found on the periodic table.

Remember that conversion is made easier with mole ratio conversion factor.

1 mole of a substance == molar mass

1 mole of a gaseous substance = molar volume

1 mole of substance = Avogadro’s number

## Step 4: Use the mole ratio from the balanced equation

Use the coefficients from the balanced chemical equation to set up a mole ratio between the given substance and the substance you are trying to find.

This mole ratio is based on the stoichiometry of the reaction and ia always used tpo relate two substances in every stoichiometry problem.

## Step 5: Calculate the moles of the substance you are trying to find

Use the mole ratio and the number of moles of the given substance to calculate the number of moles of the substance you are trying to find.

This comparison of moles is based on a balanced chemical equation and from the comparison we can then convert the moles to any amount or parameter we want to.

comparing mole ratio

Mg + 2HCl ====MgCl2 + H2

The two substances mentioned are

1 mole of Mg ===== 1 mole of MgCl2

## Step 6: Convert the moles of the substance to the desired unit

You need to study the question very well and then determine If the problem asks for mass, volume, or number of particles of the substance. Afterwards use the appropriate conversion factor to convert the moles of the substance to the desired unit.