Science Chapter 9 (multiple choice)

If the arrangement of atom sin a substance changes, then which of the following is true?

A chemical reaction has occurred

A catalyst is which of the following

Neither A or B

What has happened to the water in the illustration?

The bonds between the atoms of the water molecule have broken, and instead of water, there is now hydrogen and oxygen.

Some baking soda and vinegar.............

The two weights will be equal, because the mass is the same.

Which of the following materials will burn the fastest in open air?

a pile of small splinters

Endothermic reactions ____.

absorb more energy than they release

Breaking a chemical bond_____.

absorbs energy from the surroundings

Which of the following is certain proof that a chemical reaction has occurred?

all of the above

Which of the following is NOT a result of a chemical reaction

bubbles in boiling water

chemical reactions

can either release more energy than they absorb or absorb more energy than they release, depending on the reaction

Metallic chlorates, when heated, results in metallic chlorides and oxygen. This is a _____ reaction.

decomposition

Sodium flouride and silver nitrate become sodium nitrate and silver chloride. Carbonate and hydrogen ions become water and carbon dioxide. This is a ____ reaction.

double-replacement

All substances

have a fixed arrangement of atoms

A(n) ____ slows or stops a chemical reaction

inhibitor

Which of the following factors would NOT speed up a chemical reaction?

making the reactant particles larger

Each substance written to the right of the arrow in a chemical equation is a ____.

product

Forming a chemical bond ____

releases energy into the surroundings

An exothermic reaction

releases thermal energy

Zinc combines with hydrochloric acid, the zinc replaces hydrogen. The chemical equation for this reaction looks like: Zn + 2HCl → ZnCl2 + H2 - This is a _____ reaction

single-replacement

Sulfur trioxide reacts with water to make sulfuric acid. This is a ___ reaction

synthesis

A change in ____ is a sign of energy being used in a chemical reaction.

temperature

According to the law of conservation of mass, how does the mass of the products in a chemical reaction compare to the mass of the reactants?

the masses are always equal

Which of the following changes is chemical rather than physical

wood is burned

Atoms rearrange when

Both A and B

Why is the conservation of mass true?

All atoms at the start of a chemical reaction are present at the end of the reaction