Chemical Reaction and Environment

A change in which one or more substances are converted into new substances is a _______. (SC.8.P.9.2)

• physical change

• nuclear reaction

• chemical change

• chemical fusion

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following best describes how chemical changes differ from physical changes? (SC.8.P.9.2)

• Physical changes produce no new substances and chemical changes do.

• Physical changes always involve the formation of a gas while chemical changes may not.

• Physical changes can occur inside or outside the substance; chemical changes always occur outside.

• Physical changes involve a change of state; chemical changes involve a change of shape.

Tags

NGSS.MS-PS1-2

Jenna wants to paint her room light purple. She makes a mixture of 70% pink paint and 30% blue paint to create the shade she likes. Which of the following best describes what occurs when she mixes the paint? (SC.8.P.9.2)

• An energy change occurs as the paint's chemical properties change.

• A phase change occurs, allowing the two colors to mix evenly together.

• A chemical change occurs as the different color particles react with each other.

• A physical change occurs, since only the physical properties of the paint change.

Joey is performing an experiment in science class. He mixes two liquids in a test tube, and gas bubbles appear at the surface of the test tube. What type of changes are most likely taking place? How do you know? (SC.8.P.9.2)

• Physical change because you can separate the mixture.

• Physical change because it still is a liquid.

• Chemical change because he used chemicals.

• Chemical change because a gas formed.

Tags

NGSS.MS-PS1-2

Lena combines the ingredients for a cake and then bakes the cake. While the cake is baking, she combines butter, sugar, and milk and mixes them together to make the icing. What type of changes created the cake and the icing? (SC.8.P.9.2)

• Both the icing and the cake are formed by physical changes.

• The icing is formed by a chemical change, and the cake is formed by a physical change.

• The cake is formed by a chemical change, and the icing is formed by a physical change.

• Both the icing and the cake are formed by chemical changes.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Carbon and Oxygen react to form Carbon Dioxide. What are the reactants? (SC.8.P.9.1)

• Carbon and Dioxide

• Oxygen and Carbon

• Oxygen and Dioxide

• CO₂

Tags

NGSS.MS-PS1-1

When 16 grams of Tin and Hydrogen Fluoride react, they must produce how many grams of product? (SC.8.P.9.1)

• 32

• 8

• 20

• 16

Tags

NGSS.MS-PS1-5

How can the law of conservation of mass apply to a burning log, if all that remains of it is ash? (SC.8.P.9.1)

• The ash has the same mass as the log, although a large percentage of it blows away

• The law of conservation of mass applies to changes of state but not to chemical reactions.

• The law of conservation of mass applies to substitution and displacement reactions, but not to combustion reactions.

• The masses of the gases and water vapor released into the air by the reaction, plus the ash, equal the mass of the log before burning.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

How does the chemical equation (below) for photosynthesis shown below demonstrate the law of conservation of mass? (SC.8.P.9.1)

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

• The same number of atoms of each element are present both before and after the chemical reaction.

• The same number of each kind of molecule is present both before and after the chemical reaction.

• The same amount of water is present both before and after the chemical reaction.

• The same amount of glucose (C₆H₁₂O₆) is present both before and after the chemical reaction.

Tags

NGSS.MS-PS1-5

Adding heat to a reaction would…. (SC.8.P.9.3)

• Cause it to stop

• Cause it to speed up

• Cause it to slow down

• Not effect it at all

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4