AnswersGCSS_Physical Science_ICIntroduction to Chemical Reactions

Describing Chemical Reactions Answers

9 verified answers1 views
2
Free Preview

Which is the correctly balanced equation for the reaction of rust, Fe2O3, and hydrochloric acid, HCl?

A
Fe2O3 + HCl → FeCl3 + H2O
B
Fe2O3 +3 HCl → 2 FeCl3 + H2O
C
Fe2O3 + 6 HCl → 2 FeCl3 + 3 H2O
D
Fe2O3 + 3 HCl → 2 FeCl3 + 3 H2O
4

Cecil writes the equation for the reaction of hydrogen and oxygen below.H2 + O2 → H2O

A
to show that most molecules exist in pairs
B
to show that most compounds exist in pairs
C
to show that atoms are conserved in chemical reactions
D
to show that atoms are created in chemical reactions
7

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 equals the mass of iron and the oxygen from the air it reacted with to form the rust.
B
The mass of the rusted nail increases because iron attracts more protons from the air.
C
The increased mass of the rusted nail is an exception to the law of conservation of mass since the rusted nail’s mass increases.
D
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.
9

What can the arrow in a chemical reaction be translated to mean? Check all that apply.

A
yields
B
accompanied by
C
react to form
D
added to
E
except
10

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

Did you find these answers helpful?