Day 4 - Law of Conservation of Mass - EOG Review

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that in a closed system, the total mass of reactants before a chemical reaction is equal to the total mass of products after the reaction.

Front

What are subscripts in a chemical formula?

Back

Subscripts are numbers written below and to the right of a chemical symbol in a formula, indicating the number of atoms of that element in a molecule.

Front

Identify the subscripts in the chemical formula 3Fe₂O₄.

Back

The subscripts are 2 and 4.

Front

What is a 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

What is the coefficient in the formula 3H₂O?

Back

The coefficient is 3.

Front

How many sodium (Na) atoms are in the compound 6NaCl?

Back

There are 6 sodium (Na) atoms.

Front

What does it mean for a chemical equation to be balanced?

Back

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

Front

Which of the following is a balanced chemical equation? 4O₂ + 2H₂ + S₂ → 2H₂SO₄

Back

This equation is balanced.

Front

What happens to the total amount of matter during a chemical change?

Back

The total amount of matter stays the same.

Front

What is the purpose of balancing a chemical equation?

Back

The purpose is to ensure that the Law of Conservation of Mass is upheld, meaning that matter is neither created nor destroyed.