Counting Atoms and Balancing Equations

Front

What is a balanced chemical equation?

Back

A balanced chemical equation has the same number of each type of atom on both the reactant and product sides, indicating that mass is conserved during the reaction.

Front

How do you determine if a chemical equation is balanced?

Back

Count the number of atoms of each element on both sides of the equation. If they are equal, the equation is balanced.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that in a chemical reaction, the total mass of the reactants equals the total mass of the products.

Front

How many hydrogen atoms are in 4H₂O?

Back

There are 8 hydrogen atoms in 4H₂O (4 molecules x 2 hydrogen atoms per molecule).

Front

What is the total number of atoms in the equation: 2H₂ + O₂ -> 2H₂O?

Back

There are 6 atoms total: 4 hydrogen atoms and 2 oxygen atoms.

Front

What does it mean to balance a chemical equation?

Back

To balance a chemical equation means to adjust the coefficients in front of the compounds to ensure that the number of atoms for each element is the same on both sides.

Front

What is the coefficient in a chemical equation?

Back

A coefficient is a number placed in front of a chemical formula to indicate how many molecules or moles of that substance are involved in the reaction.

Front

How many oxygen atoms are in the equation: 2Al + 3O₂ -> 2Al₂O₃?

Back

There are 6 oxygen atoms in the products (3O₂ means 3 x 2 = 6 oxygen atoms).

Front

What is the significance of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a molecule. For example, in H₂O, the '2' indicates there are 2 hydrogen atoms.

Front

How do you find the total number of atoms in a compound?

Back

Add the number of atoms of each element together, considering their subscripts. For example, in C₆H₁₂O₆, there are 6 + 12 + 6 = 24 total atoms.