Balancing Chemical Equations

Front

What is a reactant in a chemical equation?

Back

A reactant is a substance that undergoes a chemical change in a reaction, found on the left side of the equation.

Front

What is the product in a chemical equation?

Back

A product is a substance that is formed as a result of a chemical reaction, found on the right side of the equation.

Front

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

Back

Count the subscripts in the chemical formula; if there is no subscript, it is assumed to be 1.

Front

What does it mean to balance a chemical equation?

Back

Balancing a chemical equation means ensuring that the number of atoms for each element is the same on both sides of the equation.

Front

What is the law of conservation of mass?

Back

The law states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

How many atoms are in H2SO4?

Back

There are 7 atoms in H2SO4 (2 H, 1 S, 4 O).

Front

What are coefficients in a chemical equation?

Back

Coefficients are numbers placed before compounds in a chemical equation to indicate the number of molecules or moles of that substance.

Front

How do you balance the equation: C3H8 + O2 -> CO2 + H2O?

Back

The balanced equation is: C3H8 + 5 O2 -> 3 CO2 + 4 H2O.

Front

What is the first step in balancing a chemical equation?

Back

The first step is to write down the number of atoms of each element present in the reactants and products.

Front

What is a skeleton equation?

Back

A skeleton equation is a chemical equation that shows the reactants and products but not the coefficients needed to balance it.