Law of Conservation of Matter

The drawing shows solid carbon dioxide changing into carbon dioxide gas. Which statement describes the relationship between the solid carbon dioxide and the carbon dioxide gas after all of the solid has changed to gas?

• They have the same volume.

• The gas has less volume than the solid.

• They have the same mass.

• The gas has less mass than the solid.

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NGSS.MS-PS1-5

NGSS.MS-PS1-4

When heated, mercuric oxide decomposes to form liquid mercury and oxygen. A scientist heated 10 grams (g) of mercuric oxide and formed 9.3 grams of liquid mercury. How many grams of oxygen were formed?

• 0.7 g

• 9.3 g

• 10.0 g

• 19.3 g

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

Sodium sulfate and barium chloride react with each other to form sodium chloride and barium sulfate as shown. Which statement MOST accurately describes the mass of the reactants compared to the mass of the products?

• The mass of the reactants is the same as the mass of the products.

• The products have a greater mass because matter was created during the reaction.

• The reactants have a greater mass because some of the mass was converted to heat.

• The reactants have a greater mass because some matter was destroyed by the reaction.

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

When a mixture of oxygen and hydrogen is ignited in a test tube, the reaction shown occurs. What happens to the total mass of the contents of the test tube?

• The total mass increases.

• The total mass decreases.

• The total mass remains the same.

• Part of the mass is changed to heat energy.

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NGSS.MS-PS1-5

NGSS.MS-PS1-2

Which of the following is a correctly written chemical equation that demonstrates the conservation of mass?

• Mg + HC1 --> H₂ + MgCl₂

• H₂O + CO₂ --> H₂CO₃

• KC1O₃ --> KC1 + O₂

• H₂ + O₂ --> H₂O

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NGSS.MS-PS1-5

How many nitrogen atoms does NH₃ have?

• 1
• 2
• 3
• 4

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NGSS.MS-PS1-1

What is the Law of Conservation of matter?

• Matter is created in a chemical reaction

• Matter is created in a physical change

• New chemicals formed from a chemical reaction have a larger overall matter than the original reactants

• Matter is never created or destroyed

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NGSS.MS-PS1-5

An oreo cookie weighs 20 grams.  It gets crushed into crumbs for a recipe.  How much do its crumbs weigh?

• 15 grams
• 25 grams
• 20 grams

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NGSS.MS-PS1-2

If the mass of a chemical reaction's product is 15 grams, what would the mass of the reactants be?

• 20 g

• 15 g

• 10 g

• 3 g

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NGSS.MS-PS1-5

If a chemical reaction occurs in an open system (not contained), what might happen to the measurable mass of the products when compared to the reactants?

• the measurable mass might decrease because any gas produced can escape (the actual mass would stay the same)

• the mass would increase because mass was created

• the measurable mass would stay the same because nothing would be able to leave the system.

• it depends on the type of reaction

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2