2nd - Counting Atoms, Classifying and Balancing Equations

Front

What are reactants in a chemical equation?

Back

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

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.

Front

What is a combustion reaction?

Back

A combustion reaction is a chemical reaction that occurs when a substance combines with oxygen, releasing energy in the form of light and heat.

Front

How do you determine the number of atoms in a molecule?

Back

Count the subscripts in the chemical formula; for example, in H2O, there are 2 hydrogen atoms and 1 oxygen atom.

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.

Front

What is a product in a chemical equation?

Back

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

Front

How do you balance the equation H2 + Cl2 -> HCl?

Back

The balanced equation is H2 + Cl2 -> 2HCl, indicating that 1 molecule of hydrogen reacts with 1 molecule of chlorine to produce 2 molecules of hydrochloric acid.

Front

What is an unbalanced equation?

Back

An unbalanced equation does not have the same number of each type of atom on both sides, meaning it does not obey the law of conservation of mass.

Front

What is the significance of coefficients in a chemical equation?

Back

Coefficients indicate the number of molecules or moles of a substance involved in the reaction.

Front

How many total atoms are in 4H2O?

Back

There are 12 total atoms in 4H2O (8 hydrogen and 4 oxygen).