Chemical Reactions

Question 1

Mistakes in designs of experiments making certain result more likely is an experimental ___ .

Accepted Answer

bias

Question 2

What's the chemical equation? Sodium reacts with oxygen in a 2:1 ratio to produce sodium oxide.

Accepted Answer

4 Na + O2 --> 2 Na2O

Question 3

Chemistry is the study of ____ and how it changes.

Accepted Answer

matter

Question 4

A material used to decrease the rate of a chemical reaction is a(n)

Accepted Answer

inhibitor.

Question 5

When hydrogen reacts with oxygen to form water this is a ___ reaction

Accepted Answer

synthesis

Question 6

Which of the following is an example of how to supply activation energy to begin a reaction?

Accepted Answer

Heat the reaction flask on a hot plate

Question 7

CaCO3 represents a chemical

Accepted Answer

formula.

Question 8

The rate of a chemical reaction is __________ temperature.

Accepted Answer

dependent on

Question 9

In chemical reactions, what does the principle of conservation of mass mean?

Accepted Answer

Matter is not created or destroyed.

Question 10

A precipitate is a(n) _____ that forms from solution during a chemical reaction.

Accepted Answer

solid

Question 11

When existing bonds break and new bonds form _____ changes occur .

Accepted Answer

Chemical

Question 12

The principle of conservation of mass is true

Accepted Answer

for reactions in both open and closed systems.

Question 13

Is the reaction that occurs in the diagram endothermic or exothermic?

Accepted Answer

Exothermic, gives off energy

Question 14

Does it take energy to make hydrogen gas and oxygen gas react to form water?

Accepted Answer

yes

Question 15

A chemical reaction may be detected by observing changes in the ____ of matter.

Accepted Answer

properties

Question 16

Chemicals that act as biological catalysts by speeding up reactions in living things are called

Accepted Answer

enzymes.

Question 17

What is the first rule you should follow if you have an accident while doing a lab?

Accepted Answer

tell the teacher

Question 18

Chemical reactions in living things would not be possible without the ___ found in cells.

Accepted Answer

enzymes

Question 19

The products formed are mostly (C), (CO2), and (H2O), what elements were the reactants?

Accepted Answer

H, C, O

Question 20

The process of making a more complex compound from simpler substances is _______.

Accepted Answer

A synthesis reaction

Question 21

Is the reaction that occurs in the diagram endothermic or exothermic?

Accepted Answer

Exothermic, energy given off

Question 22

The only sure evidence for a chemical reaction is

Accepted Answer

the production of one or more new substances.

Question 23

The candle liquefied, ran down the side and solidified. Is this physical or chemical change?

Accepted Answer

Physical

Question 24

The _____ is the minimum amount of energy that must be added to start a chemical reaction.

Accepted Answer

activation energy

Question 25

The amount of matter in a chemical reaction _________.

Accepted Answer

does not change

Question 26

A bottle of hydrogen peroxide eventually turns into a bottle of water and oxygen gas this is a:

Accepted Answer

decomposition reaction.

Question 27

In a chemical equation, the substances written on the right side of the arrow are called ___.

Accepted Answer

products

Question 28

Reasoning that relies on gathering and evaluating evidence is ______ reasoning.

Accepted Answer

Objective

Question 29

Where one element replaces another or where two elements trade places is a(n) ____ reaction.

Accepted Answer

replacement

Chemical Reactions

Questions 29

Chemical Reactions

Questions 29