Lesson 19 Classwork

Front

What is a coefficient in a chemical equation?

Back

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

Front

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

Back

To determine the number of atoms in a compound, multiply the subscript of each element by the coefficient in front of the compound. For example, in 2H2O, there are 4 H atoms and 2 O atoms.

Front

What does it mean for a chemical equation to be balanced?

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

How many hydrogen and oxygen atoms are in the compound 3H2O?

Back

There are 6 hydrogen atoms and 3 oxygen atoms in 3H2O.

Front

What is the balanced equation for the combustion of propane (C3H8)?

Back

The balanced equation is C3H8 + 5O2 → 3CO2 + 4H2O.

Front

What is the purpose of balancing chemical equations?

Back

The purpose of balancing chemical equations is to ensure that the law of conservation of mass is followed, meaning that matter is neither created nor destroyed in a chemical reaction.

Front

What are the steps to balance a chemical equation?

Back

1. Write the unbalanced equation. 2. Count the number of atoms of each element on both sides. 3. Adjust coefficients to balance the atoms. 4. Repeat until all elements are balanced.

Front

What is the significance of the subscript in a chemical formula?

Back

The subscript indicates the number of atoms of the element in one molecule of the compound. For example, in H2O, the '2' indicates there are 2 hydrogen atoms.

Front

How do you identify the limiting reactant in a chemical reaction?

Back

The limiting reactant is the substance that is completely consumed first in a chemical reaction, limiting the amount of product formed.

Front

What is the difference between a reactant and a product?

Back

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