Matter and Energy Day 3

Matter and Energy Day 3

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Multiple Choice

Which statement best describes evidence that a chemical reaction occurs as a cake bakes?

• The water in the cake batter evaporates

• The cake rises as gas bubbles form in the baking cake

• The cake takes the shape of the container in which it is baked

• The water in the cake batter is used to keep the cake moist as it bakes

Multiple Choice

Students combined substances in a beaker to observe chemical reactions. The table shows their observations. Assuming the students did not make any careless errors, what likely explains these changes in mass?

• Procedure 1: All the reactants were liquids that evaporated.

  Procedure 2: A gas was formed as one product, and it escaped into the air.

• Procedure 1: One of the reactants was converted to thermal energy.

  Procedure 2: All the products were liquids.

• Procedure 1: The reactants were liquids with different densities.

  Procedures 2: The reactants were combined into only one product.

• Procedure 1: One of the products was a gas that escaped into the air.

  Procedure 2: A gas from the air reacted with one of the other reactants.

Multiple Choice

A strip of shiny metal was placed into a beaker of blue solution and left on a shelf overnight. The next morning these observations were recorded.

Can the student conclude that a chemical reaction occurred?

• No, because the metal strip was still visible

• Yes, because a new material of a different color formed on part of the metal strip

• No, because the solution stayed blue

• Yes, because the volume of the blue solution stayed the same

Multiple Choice

The equation for producing nitrogen dioxide is shown below.

Which of these provides evidence that a chemical reaction occurs?

• A gas is present

• The total number of atoms remains unchanged.

• The state of matter remains the same.

• A brown gas is produced.

Multiple Choice

What mass of calcium carbonate, to the nearest hundredth, is decomposed in this reaction?

• 6.03

• 6

• 50

• 49.97

Multiple Choice

All the following reactions are correctly balanced except -

• 2C₂H₂ + 5O₂ ---> 4CO₂ + 2H₂O

• 4Fe + 3O₂ ---> 2Fe₂O₃

• NaHCO₃ ---> Na₂CO₃ + H₂O + CO₂

Multiple Choice

What is the Law of Conservation of Mass?

• It states that matter cannot be created or destroyed.

• It states that energy cannot be created or destroyed.

• It states that matter can be created or destroyed.

• It states that sound can be created or destroyed.

Multiple Choice

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants

• Products 

• Yields 

• Chemical Equation 

Multiple Choice

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

• Reactants

• Products 

• Yields 

• Chemical Equation 

Multiple Choice

How many atoms of carbon (C) are in C₆H₁₂O₆?

• 3

• 6

• 12

• 24

Multiple Choice

How many Sodium (Na) are in 6NaCl?

• 1

• 12

• 6

Multiple Choice

How many atoms are there TOTAL in:
H₂SO₄

• 6

• 5

• 7

• 3