Unit 8: Reactions & Equations Check for Understanding

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. This means that the total mass of the reactants must equal the total mass of the products.

Front

Why is it important to balance chemical equations?

Back

It is important to balance chemical equations to ensure that the same number of each type of atom is present on both sides of the equation, in accordance with the law of conservation of mass.

Front

What are reactants in a chemical equation?

Back

Reactants are the substances that undergo a chemical change in a reaction. They are found on the left side of a chemical equation.

Front

What are products in a chemical equation?

Back

Products are the substances that are formed as a result of a chemical reaction. They are found on the right side of a chemical equation.

Front

How do you balance the equation: Na + Cl2 -> NaCl?

Back

The balanced equation is 2Na + Cl2 -> 2NaCl.

Front

How do you balance the equation: Fe + O2 -> Fe2O3?

Back

The balanced equation is 4Fe + 3O2 -> 2Fe2O3.

Front

How do you balance the equation: H2 + O2 -> H2O?

Back

The balanced equation is 2H2 + O2 -> 2H2O.

Front

What is a chemical equation?

Back

A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products along with their quantities.

Front

What is the difference between a coefficient and a subscript in a chemical formula?

Back

A coefficient indicates the number of molecules or moles of a substance, while a subscript indicates the number of atoms of an element in a molecule.

Front

What is a skeleton equation?

Back

A skeleton equation is a chemical equation that shows the reactants and products but not their coefficients, indicating that it is unbalanced.