Chemical Equations

Balancing chemical equations:

Balancing chemical equations is the process of making sure that there is an equal number of atoms of each element on both sides of the equation. To balance a chemical equation, you need to follow these steps:

1. Write down the unbalanced equation: Begin by writing the chemical equation you want to balance.
2. Count the number of atoms on each side: Next, count the number of atoms of each element on both the reactant (left-hand) side and the product (right-hand) side of the equation.
3. Add coefficients to balance the equation: To balance the equation, you need to add coefficients (numbers in front of the chemical formulas) to each element so that the number of atoms on each side is the same. Start with the most complex or abundant element and work your way to the less complex ones.
4. Check to make sure the equation is balanced: Once you have added coefficients to each element, check to see that the number of atoms of each element is the same on both sides of the equation. If the equation is not balanced, continue adding coefficients until it is.
5. Write the balanced equation: Finally, write the balanced equation by placing the coefficients in front of the chemical formulas.

It is important to note that you should never change the subscripts of the chemical formulas when balancing the equation. Only add coefficients to balance the equation.

Website to double check answers

2Fe + 3Cl2 → 2FeCl3

2KMnO4 + 16HCl → 2KCl + 2MnCl2 + 8H2O + 5Cl2

Mass to Mass Stoichiometry:

Moles to Mass and Mass to moles

Mass to mass stoichiometry is a type of calculation in chemistry that relates the masses of reactants and products in a chemical reaction. The stoichiometric coefficients in a balanced chemical equation are used to convert the mass of one substance to the mass of another substance.

What mass of iron produces 13 grams of iron chloride?

2Fe + 3Cl2 → 2FeCl3

$=\frac{2}{2} \times \frac{molar mass(Fe)}{molar mass(FeCl_2)}\times13$

$=\frac{2}{2} \times \frac{55.845}{126.751}\times13$

$=5.728$

Limiting Reagent

The limiting reagent is the reactant that gets completely consumed in a reaction, thereby limiting the amount of product that can be formed. The other reactants that are not completely consumed are referred to as excess reagents.

Here are some examples:

1. Suppose you want to make sandwiches and you have 4 slices of bread and 2 slices of ham. The limiting reagent in this scenario is the ham because you cannot make more than 2 sandwiches since you only have 2 slices of ham.

2. In a chemical reaction where hydrogen gas (H2) reacts with oxygen gas (O2) to form water (H2O), if you have 6 moles of H2 and 2 moles of O2, the limiting reagent is O2. This is because the balanced equation for the reaction is 2H2 + O2 → 2H2O, which means that for every 1 mole of O2 consumed, 2 moles of H2 are also consumed. Therefore, you can only form 2 moles of H2O, which is the maximum amount possible with the given amounts of H2 and O2.

3. Another example is a reaction between iron (III) oxide (Fe2O3) and carbon monoxide (CO) to produce iron (Fe) and carbon dioxide (CO2), Fe2O3 + 3CO → 2Fe + 3CO2. If you have 2 moles of Fe2O3 and 3 moles of CO, the limiting reagent is CO since it requires 3 moles of CO to react with 1 mole of Fe2O3. Therefore, you can only produce 2 moles of Fe and 3 moles of CO2.