Physical Science: Balancing Equations

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that in a closed system, the mass of the reactants must equal the mass of the products in a chemical reaction.

Front

What does it mean to balance a chemical equation?

Back

Balancing a chemical equation means adjusting the coefficients of the reactants and products so that the number of atoms of each element is the same on both sides of the equation.

Front

What is a coefficient in a chemical equation?

Back

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

Front

How do you determine the coefficients for the reaction N2 + O2 -> NO?

Back

To balance the equation, you need 1 N2, 1 O2, and 2 NO, resulting in the coefficients 1, 1, 2.

Front

Why is it incorrect to say that gases weigh nothing in a chemical reaction?

Back

Gases have mass, and their mass must be accounted for in a chemical reaction, as it contributes to the total mass of reactants and products.

Front

How many HCl molecules are needed to balance the equation Mg + __HCl -> MgCl2 + H2?

Back

You need 2 HCl molecules to balance the equation.

Front

What happens to the total mass of reactants in a sealed reaction?

Back

The total mass of the reactants remains the same as the total mass of the products in a sealed reaction.

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations is crucial because it reflects the conservation of mass and allows for accurate stoichiometric calculations.

Front

What is the difference between reactants and products in a chemical reaction?

Back

Reactants are the starting substances that undergo a chemical change, while products are the substances formed as a result of the reaction.

Front

What is an example of a balanced chemical equation?

Back

An example of a balanced chemical equation is: 2H2 + O2 -> 2H2O.