Quiz on Mass and Conservation of Mass

The amount of matter in an object is its ___________.

• volume

• density

• mass

• weight

Answer explanation

The amount of matter in an object is referred to as its mass. Mass is a measure of the quantity of matter, while volume measures space occupied, density is mass per unit volume, and weight is the force of gravity on an object.

Balance the chemical equation: ___FeBr₃ + ___H₂SO₄ → ___Fe₂(SO₄)₃ + ___HBr

• 2FeBr₃ + 3H₂SO₄ → Fe₂(SO₄)₃ + 6HBr

• FeBr₃ + H₂SO₄ → Fe₂(SO₄)₃ + HBr

• 2FeBr₃ + 3H₂SO₄ → 2Fe₂(SO₄)₃ + 3HBr

• 2FeBr₃ + 3H₂SO₄ → Fe₂(SO₄)₃ + 3HBr

Answer explanation

To balance the equation, we need 2 FeBr₃ to provide 2 Fe and 6 Br, and 3 H₂SO₄ to provide 3 SO₄. This results in 1 Fe₂(SO₄)₃ and 6 HBr, making the balanced equation: 2FeBr₃ + 3H₂SO₄ → Fe₂(SO₄)₃ + 6HBr.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

True or False: Mass is conserved in physical but not chemical changes in matter.

• True

• False

Answer explanation

False is correct because mass is conserved in both physical and chemical changes. In any transformation, the total mass of the reactants equals the total mass of the products, adhering to the law of conservation of mass.

Tags

NGSS.MS-PS1-5

When a candle burns, all that remains is a small puddle of wax. The rest of the candle’s mass was

• destroyed

• changed to gases

• measured incorrectly

• none of above

Answer explanation

When a candle burns, the wax undergoes a chemical reaction, primarily turning into gases like carbon dioxide and water vapor. Thus, the mass that disappears is not destroyed but changed to gases.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A puddle of water slowly shrinks in the sun. After a few hours, the puddle has dried up completely. Is this an exception to the Law of Conservation of Mass?

• Yes, because the water disappears.

• No, because the water evaporates into the air.

• Yes, because mass is lost.

• No, because mass is destroyed.

Answer explanation

The water evaporates into the air, changing from liquid to gas. This process does not violate the Law of Conservation of Mass, as the total mass remains constant; it simply changes form.

Tags

NGSS.MS-PS1-5

True or False: Fire destroys the mass of the fuel that it burns.

• True

• False

Answer explanation

False is correct because fire does not destroy the mass of the fuel; it transforms it into other substances like gases and ash. The total mass is conserved according to the law of conservation of mass.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

True or False: The products of a chemical reaction can never have greater mass than the reactants.

• True

• False

Answer explanation

True. According to the law of conservation of mass, the total mass of reactants in a chemical reaction equals the total mass of the products. Therefore, products can never have greater mass than reactants.

Tags

NGSS.MS-PS1-5

Balance the chemical equation: ___C₅H₁₂ + ___O₂ → ___CO₂ + ___H₂O

• C₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O

• C₅H₁₂ + 8O₂ → 5CO₂ + 12H₂O

• C₅H₁₂ + 8O₂ → 5CO₂ + 5H₂O

• C₅H₁₂ + 8O₂ → 5CO₂ + 8H₂O

Answer explanation

To balance the equation, count the atoms: C₅H₁₂ has 5 C and 12 H. It needs 5 CO₂ (5 C) and 6 H₂O (12 H). For O, 5 CO₂ gives 10 O and 6 H₂O gives 6 O, totaling 16 O. Thus, 8 O₂ is required. The correct equation is C₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O.

Tags

NGSS.MS-PS1-5

In science, a law is

• A rule governing what you are permitted to do.

• A general rule about how the physical universe works.

• A legal document that describes a rule of conduct.

• A statute enacted by a legislative body.

Answer explanation

In science, a law is defined as a general rule about how the physical universe works, describing consistent relationships observed in nature, unlike legal documents or statutes.

What is true about a substance with a lot of mass?

• It contains a lot of matter.

• It has a large volume.

• It has a high density of particles.

• It has low frequency.

Answer explanation

A substance with a lot of mass indeed contains a lot of matter, as mass is a measure of the amount of matter in an object. The other options do not necessarily correlate with mass.