AnswersPhysical ScienceDescribing Chemical Reactions

Describing Chemical Reactions — Quiz Answers

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Rust results from iron’s reaction to oxygen. An iron nail gains mass when it rusts. How does this reaction support the law of conservation of mass?

A
The mass of the rusted nail increases because iron attracts more protons from the air.
B
The increased mass of the rusted nail results from the rearrangement of protons and neutrons within oxygen, according to the law of conservation of mass.
C
The mass of the rusted nail equals the mass of iron and the oxygen from the air it reacted with to form the rust.
D
The increased mass of the rusted nail is an exception to the law of conservation of mass since the rusted nail’s mass increases.
3

Cecil writes the equation for the reaction of hydrogen and oxygen. cap h sub 2 plus cap o sub 2 rightarrow cap h sub 2 cap o Why does his teacher ask him to balance the equation by including the correct coefficients?

A
to show that atoms are conserved in chemical reactions
B
to show that atoms are created in chemical reactions
C
to show that most molecules exist in pairs
D
to show that most compounds exist in pairs
4

Franklin was performing an experiment by combining hydrochloric acid and sodium hydroxide. He measured the mass of his reactant materials to be 35 g. The reaction resulted in the production of salt and water. He reported that his products weighed 32 g. Which best describes the results of Franklin’s experiment?

A
No error occurred, water is not weighed when determining the weight of the products.
B
An error occurred, the products should weigh more than the reactants.
C
An error occurred, the mass of the reactants should equal the mass of the products.
D
No error occurred, some of the products are always lost as heat.
7

Which equation best represents the law of conservation of mass?

A
mass of reactants minus mass of product is equal to mass conserved
B
mass of reactants is equal to mass of products
C
mass of reactants is greater than mass of products
D
mass of reactants plus mass of products is equal to mass conserved
8

Liquid 1 reacts with Liquid 2 , producing a solid and a gas. Using this scenario, which supports the law of conservation of mass?

A
mass of liquid 1 minus mass of solid is equal to mass of liquid 2 minus mass of gas
B
mass of liquid 1+ mass of liquid 2=mass of solid +mass of gas
C
mass of liquid 1− mass of liquid 2=mass of solid +mass of gas
D
mass of liquid 1 plus mass of solid is equal to mass of liquid 2 plus mass of gas
9

The expression CaCO sub 3 rightarrow CaO plus CO sub 2 is an example of a

A
reactant.
B
product.
C
chemical equation.
D
chemical progression.

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