Balancing Chemical Equations Practice

What does it mean if a chemical equation is already balanced?

• It means that the equation has been simplified for easier understanding.

• It indicates that the number of atoms of each element is the same on both sides of the equation, and no further adjustments are needed.

• It shows that the reaction has reached completion and no more products can be formed.

• It suggests that the equation is incorrect and needs to be re-evaluated.

What is a balanced chemical equation?

• A balanced chemical equation has equal numbers of each type of atom on both sides of the equation, indicating that mass is conserved during the reaction.

• A balanced chemical equation shows the total energy released during a reaction.

• A balanced chemical equation lists the reactants and products without any coefficients.

• A balanced chemical equation is one that has unequal numbers of atoms on each side.

How many manganese (Mn) atoms are in 3Cr(MnO4)6?

• 12

• 15

• 18

• 21

What is the difference between a molecular formula and an empirical formula?

• A molecular formula shows the simplest whole-number ratio of the elements, while an empirical formula shows the actual number of atoms of each element in a molecule.

• A molecular formula shows the actual number of atoms of each element in a molecule, while an empirical formula shows the simplest whole-number ratio of the elements.

• A molecular formula is always larger than the empirical formula, regardless of the compound.

• A molecular formula is used only for ionic compounds, while an empirical formula is used for covalent compounds.

What is the first step in balancing a chemical equation?

• To write the unbalanced equation and count the number of atoms of each element on both sides.

• To identify the products of the reaction.

• To add coefficients to the reactants and products.

• To ensure that the number of molecules is equal on both sides.

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

• Add the subscripts of each element together.

• Multiply the subscript of each element by the coefficient in front of the compound.

• Count the number of elements in the compound.

• Divide the total number of atoms by the number of elements.

What is the significance of subscripts in a chemical formula?

• They indicate the type of chemical reaction.

• They represent the molecular weight of the compound.

• They indicate the number of atoms of each element in a molecule; for example, in H2O, the '2' indicates there are two hydrogen atoms.

• They show the state of matter of the compound.

What is the purpose of balancing chemical equations?

• To ensure that the same number of each type of atom is present on both sides of the equation, reflecting the conservation of mass.

• To increase the speed of a chemical reaction.

• To determine the temperature at which a reaction occurs.

• To identify the products of a chemical reaction.

What is the law of conservation of mass?

• The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction; it can only change forms.

• Mass can be created and destroyed in a chemical reaction.

• The total mass of a closed system remains constant over time.

• Mass is only conserved in physical changes, not in chemical reactions.

What is a reactant in a chemical reaction?

• A substance that undergoes change during a chemical reaction, found on the left side of the equation.

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

• A catalyst that speeds up the chemical reaction without being consumed.

• A byproduct that is released during a chemical reaction.