Module 8 Review - Chemical Reactions

the starting materials in a chemical reaction

• Products
• Reactants
• Starters
• Enders

a substance that is formed as the result of a chemical reaction

• Product 
• Reactant
• Starters
• Enders

In the equation,          2Mg + O₂ ---> 2MgO, which are the reactants?

• Mg and O
• MgO
• Mg and MgO
• O and MgO

Which of the following is an example that includes evidence of a chemical reaction?

• A sample of zinc is placed in water and it settles to the bottom
• A solid block of ice is heated and it completely melts into a liquid. 
• Sugar that is burned gives off an odor and turns brown and then black.
• A tomato is placed into a blender and chopped up into smaller pieces.

A precipitate is a 

• liquid that forms when two solids are reacted
• a solid that forms when two liquids are mixed
• a gas that forms when vinegar and baking soda react
• a change of color in a solution

What is the Law of Conservation of mass?

• Mass is created in a chemical reaction
• Mass is created in a physical change
• New chemicals formed from a chemical reaction have a larger overall mass than the original reactants
• Mass is never created or destroyed

When a chemical reaction occurs, what is made?

• No new substance is made.
• A new substance is made with new atoms formed
• A new substance is made, with existing atoms rearranged
• All substances remain the same, but physical state may change.

Solid sodium metal reacts with chlorine gas to form solid sodium chloride. Which of the following is a correct word equation for this reaction?

• Sodium (m) --> Chlorine (s) + Sodium Chloride (s)

• Sodium (s) + Chlorine (g) --> Sodium Chloride (s)

• Sodium metal + chlorine gas --> Sodium chloride

• Na + Cl --> NaCl

What does (aq) mean in a chemical equation?

• a substance is dissolved in water

• a substance is dissolved in alcohol

• a substance is a liquid

• a substance is a solid

"Solid zinc oxide is produced by combining zinc powder with oxygen gas." What is the correct skeleton equation for this reaction?

• ZnO (s) --> Zn (s) + O₂ (g)

• ZnO (s) --> Zn + O (g)

• Zn (s) + O₂ (g) --> ZnO (s)

• Zn + O --> ZnO