Chemical equations should be balanced so that they demonstrate the law of conservation of mass. Which of the following statements about balanced chemical equations is correct?
a
The products must contain the same numbers and types of atoms as the reactants.
b
The products must contain the same numbers but not the same types of atoms as the reactants.
c
The products must contain the same arrangement of atoms as found in the reactants.
d
The products must contain the same types but not the same numbers of atoms as the reactants.
a) The products must contain the same numbers and types of atoms as the reactants.
The correct statement about balanced chemical equations is: a) The products must contain the same numbers and types of atoms as the reactants.
The correct statement about balanced chemical equations is option a: "The products must contain the same numbers and types of atoms as the reactants."
To balance a chemical equation, you need to ensure that the number of each type of atom on both sides of the equation is the same. The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction, only rearranged. Therefore, the total mass of the reactants must be equal to the total mass of the products.
To balance a chemical equation, you can follow these steps:
1. Write down the unbalanced equation with the correct formulas for the reactants and products. For example:
H2 + O2 → H2O
2. Count the number of atoms on both sides of the equation.
In the reactants: 2 hydrogen atoms and 2 oxygen atoms.
In the product: 2 hydrogen atoms and 1 oxygen atom.
3. Begin by balancing the atoms that appear in the most compounds or elements. In this example, there are only two elements, hydrogen and oxygen. Start by balancing the hydrogen atoms.
Adding a coefficient of 2 in front of the water molecule (H2O) will balance the number of hydrogen atoms:
H2 + O2 → 2H2O
4. Check the number of oxygen atoms on both sides of the equation.
On the left side: 2 oxygen atoms
On the right side: 4 oxygen atoms
5. To balance the oxygen atoms, add a coefficient of 2 in front of the oxygen molecule (O2):
H2 + 2O2 → 2H2O
Now the equation is balanced, and it shows that the reactants (H2 and O2) combine to form the product (H2O), which contains the same numbers and types of atoms.