Balancing Chemical Equations

Front

What is a balanced chemical equation?

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 during the reaction.

Front

What does a subscript in a chemical formula indicate?

Back

A subscript is the small number below the element symbol that tells the number of atoms of that element in a molecule.

Front

How do you determine the number of atoms in a compound with parentheses?

Back

Multiply the subscript outside the parentheses by the subscripts of each element inside the parentheses.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction.

Front

How many hydrogen atoms are in 3(NH₄)₂CrO₄?

Back

24

Front

How many magnesium atoms are in 10MgCl₂?

Back

10

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 do you balance the equation Mg + HCl -> MgCl₂ + H₂?

Back

You need 2 HCl to balance the equation.

Front

What is the first step in balancing a chemical equation?

Back

Identify and write down the number of atoms of each element present in the reactants and products.

Front

What does it mean if a chemical equation is not balanced?

Back

It means that the number of atoms of at least one element is different on the reactant side compared to the product side.