Introduction to Chemistry

The data from an investigation on the reaction of sodium and chlorine is shown in the table above.  The data in the table gives evidence to support the fact that

• compounds have different properties than the elements that make them up

• crystals are formed whenever solids react with gases

• once a compound is formed it cannot be chemically separated into the elements from which it is made.

• chlorine has a higher melting point than sodium

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NGSS.MS-PS1-2

The chemical word equation for the process of photosynthesis is:carbon dioxide + water → glucose + oxygen

The reactant(s) for the process of photosynthesis

 

• are glucose and oxygen

• is glucose only

• is water only

• are water and carbon dioxide

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NGSS.MS-LS1-6

Which of the following is a physical property of water?

• It reacts with calcuim metal to produce a basic solution

• It can be decomposed by electrolysis

• It forms a new compound when reacted with Magnesium

• It melts below room temperature

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NGSS.MS-PS1-4

Some properties are the same in a substance no matter the amount of the substance. Which of the following characteristics does not change based on the amount of the substance?

• Mass

• Volume

• Density

• Weight

.  In the food industry, manufacturers turn vegetable oil into margarine through the process of hydrogenation.  This chemical reaction occurs at the fastest rate and with the lowest activation energy when

• a nickel catalyst is used

• more reactant is added to the reaction

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NGSS.HS-PS1-5

As collisions increase between reactants, the rate of reaction also increases.  Which of the following does not cause an increase in collisions between reactants?

• increase in temperature

• decrease in surface area

• increase in pressure

• addition of a catalyst

Which of the following is a chemical change?

• mixing

• melting

• rusting

• grinding

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NGSS.MS-PS1-2

NGSS.MS-PS1-5

During a chemical reaction in which a catalyst has been added, the amount of the catalyst

• increases

• decreases

• does not change

• fluctuates

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NGSS.MS-PS1-5

For a reaction such as:

Na + 2H₂O → Na(OH)₂ + H₂

At which temperature will the rate of the reaction be the fastest ?

• 40 degree C

• 60 degree C

• 20 degree C

• 0 degree C

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A student adds a small amount of acid to a buffer solution that has a pH of 9.5. Which of the following happens?

• The acid shows an increase in pH from 9.5

• The pH of the solution falls as a constant rate until it reaches 4.5

• The pH of the solution remains about 9.5

• The solution rapidly becomes neutral