Chemical Reactions and Matter

Chemical Reactions

Multiple Choice

Look at the picture of the equation provided. Which of the following indicates that a chemical reaction may be present? (CHECK STATES OF MATTER)

• Gas evolution

• Water production

• Precipitate formation

• Changes in energy to system

Multiple Choice

Which of the following equations demonstrates an actual chemical reaction that forms a new substance?

• A

• B

• C

• D

Multiple Choice

A student heated a 10 gram sample of a chemical in an open container. A chemical reaction occurred, and the mass of the sample was measured again. The mass of the sample was found to be less than before the reaction. Which of the following best explains the decrease in mass of the sample?

• The heat caused the chemical to become less dense.

• The reaction gave off more heat than was added.

• Some of the lighter particles were destroyed.

• Some of the particles escaped as a gas formed.

Multiple Choice

Which of the models of a chemical reaction best represents the Law of Conservation of Mass?

• A

• B

• C

• D

Last but not least: Types of reactions!

• Look at what is before and after the arrow!

• Find the pattern

• Don't forget about Combustion, students always forget that one exists.

Multiple Choice

What type of reaction is the following: $$2NaHCO_3->\ Na_2CO_3+CO_2+H_2O$$  

• Combination

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Multiple Choice

What type of reaction is the following: $$BaCl_2+2KI\ ->\ 2KCl\ +\ BaI_2$$  

• Combination

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Multiple Choice

What are the coefficients that will balance the skeleton equation below?

__MgS + __O₂ → __MgO + __SO₂

• 3,2,2,3

• 2,3,2,2

• 2,3,2,3

• 3,2,2,1

Multiple Choice

What are the coefficients that will balance the skeleton equation below?

__Na + __F₂ → __NaF

• 1, 2, 1

• 2, 1, 2

• 1,1,1

• 2,2,2