Chemical Reacations and Conservation of Matter

Multiple Choice

What is another term used to describe chemical changes?

• Physical reactions

• Chemical reactions

• Physical changes

• Energy changes

Multiple Choice

Which of the following best describes the difference between reactants and products in a chemical reaction?

• Reactants are created in the reaction, products take part in the reaction

• Reactants are substances that take part in the reaction, products are created in the reaction

• Reactants and products are the same

• Reactants are always gases, products are always solids

• Both sides of the chemical reaction are called chemical equations.

Multiple Choice

Based on the chemical equation Na + Cl → NaCl, identify the reactants and the product.

• Reactants: NaCl; Product: Na and Cl

• Reactants: Na and Cl; Product: NaCl

• Reactants: Na; Product: Cl and NaCl

• Reactants: Cl; Product: Na and NaCl

Multiple Choice

Which statement best describes the Law of Conservation of Matter as shown in the slides?

• Matter can be created and destroyed during a chemical reaction.

• Mass cannot be created or destroyed, and whatever is on one side of a chemical reaction must be on the other.

• Atoms change their identity during a chemical reaction.

• Energy is always conserved in every chemical reaction.

Fill in the Blanks

The number of magnesium atoms on the reactants side is

to the number of magnesium atoms on the products side.

Multiple Select

Which of the following are true about the atoms in the reactants and products in the magnesium and oxygen reaction?

• The number of magnesium atoms is the same on both sides.

• The number of oxygen atoms is the same on both sides.

• The type of atoms changes during the reaction.

• The total number of atoms is conserved.

Multiple Choice

Which part of a chemical equation tells you the quantity of each element or formula present?

• Coefficient

• Subscript

• Arrow

• Chemical Symbol

Multiple Select

Select all the correct statements about the reactants and products in the equation Na + Cl₂ → NaCl.

• Na and Cl₂ are reactants.

• NaCl is the product.

• Cl₂ is a product.

• Na is a product.

Fill in the Blanks

The chemical equation 2Na + Cl₂ → 2

represents the balanced reaction for sodium and chlorine. Fill in the blank.

Fill in the Blanks

Another word for chemical changes is

Open Ended

Summarize the main differences between chemical and physical changes, and explain how you can identify if a chemical change has occurred.