Quiz about Science Unit 2: Chemical Reactions

Question 1

This image shows the product of a chemical reaction. Which is the name of the kind of solid substance formed in this type of chemical reaction?

Accepted Answer

precipitate

Answer

aqueous

Answer

acid

Answer

synthesis

Question 2

Which example provides evidence that a chemical reaction has occurred.

Accepted Answer

formation of a gas

Answer

dissolving

Answer

melting

Answer

bending

Question 3

How many oxygen atoms are present in the following?
4Ca(OH)₂

Accepted Answer

8

Answer

4

Answer

6

Answer

1

Question 4

Which of the following describes a chemical change?

Accepted Answer

gasoline burns in a car engine

Answer

water freezes to form ice

Answer

sugar dissolves in water

Answer

a piece of metal expands when it is heated

Question 5

What type of change occurs when a new substance is formed that has properties different from those of the original substances?

Accepted Answer

chemical change

Answer

nuclear change

Answer

physical change

Answer

mutation

Question 6

Which of the following describes a chemical change?

Accepted Answer

burning a piece of notebook paper in the presence of oxygen

Answer

cutting a piece of paper with scissors

Answer

cooling a mixture of air and kerosene vapor to obtain liquid kerosene

Answer

heating water over a flame to its boiling point

Question 7

In every chemical reaction, the mass of the products is always ____________________________.

Accepted Answer

the same as the mass of the reactants

Answer

slightly less than the mass of the reactants

Answer

much less than the mass of the reactants

Answer

greater than the mass of the reactants

Question 8

How many carbon atoms are present in this chemical equation?

Accepted Answer

1

Answer

2

Answer

3

Answer

4

Question 9

The left side of this equation is called ________________.

Accepted Answer

reactants

Answer

products

Question 10

The right side of this equation is called ________________.

Accepted Answer

products

Answer

reactants

Question 11

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant or product are involved in a reaction is called __________________________________.

Accepted Answer

coefficient

Answer

reactant

Answer

subscript

Answer

product

Question 12

CaCO₃ represents a chemical _______________.

Accepted Answer

formula

Answer

symbol

Answer

subscript

Answer

reaction

Question 13

In chemical reactions, what does the Law of Conservation of Mass mean?

Accepted Answer

Matter is not created or destroyed.

Answer

The total mass of the reactants is greater than the total mass of the products.

Answer

The total mass of the reactants is less than the total mass of the products.

Answer

Matter is not changed.

Question 14

How many oxygen atoms are in the molecule 2C₂HO₈C_l2?

Accepted Answer

16

Answer

2

Answer

8

Answer

5

Question 15

How many hydrogen atoms are in the compound NH₃O₅?

Accepted Answer

3

Answer

4

Answer

5

Answer

1

Question 16

What is the left side of a chemical equation called?

Accepted Answer

reactant

Answer

product

Answer

yields

Answer

chemical equation

Question 17

What is the total number of atoms present in 5Na₃PO₄?

Accepted Answer

40

Answer

5

Answer

55

Answer

8

Question 18

What is the little number found after an element symbol in a chemical formula called?

Accepted Answer

subscript

Answer

coefficient

Answer

atom

Answer

equation

Question 19

How many elements are in C₆H₁₂O₆?

Accepted Answer

3

Answer

1

Answer

2

Answer

4

Question 20

Is this chemical equation balanced?

Accepted Answer

No

Answer

Yes

Question 21

Which term best describes this substance?

Accepted Answer

compound

Answer

element

Answer

mixture

Answer

a mixture of compounds

Question 22

Which term best describes this substance?

Accepted Answer

element

Answer

compound

Answer

mixture

Answer

a mixture of elements

Question 23

Which compound has twice as many oxygen atoms as hydrogen atoms?

Accepted Answer

H2SO4

Answer

H3PO4

Answer

HClO3

Answer

H2O

Question 24

Is this a chemical change or a physical change?

Accepted Answer

physical change

Answer

chemical change

Question 25

What is a coefficient?

Accepted Answer

The large number in front of a chemical formula.

Answer

The small number on the right of the chemical symbol.

Answer

The number in between the chemical symbols.

Answer

The number behind a chemical formula.

Question 26

How many elements are in C₆H₁₂O₆?

Accepted Answer

3

Answer

1

Answer

2

Answer

4

Question 27

What are the blue numbers called?

Accepted Answer

subscripts

Answer

oxidation numbers

Answer

group numbers

Answer

product numbers

Question 28

How many molecules are shown in this chemical formula?

Accepted Answer

2

Answer

1

Answer

3

Answer

4

Question 29

In a chemical reaction, Reactant A has 5 g and Reactant B has 9 g. How many grams should Product C have?

Accepted Answer

14 g

Answer

4 g

Answer

5 g

Answer

9 g

Question 30

In a chemical reaction, Reactant A has 5 g and Product C has 9 g. How many grams should Reactant B have?

Accepted Answer

4 g

Answer

5 g

Answer

9 g

Answer

14 g

Question 31

If a substance is a compound, it is also a __________________.

Accepted Answer

molecule

Answer

mixture

Answer

element

Answer

secret

Question 32

Elements are represented by chemical symbols. Chemical symbols are written with _____________________________.

Accepted Answer

at least one capital letter

Answer

all lower case letters

Answer

all capital letters

Answer

using the 1st letter of the name

Question 33

Which description best represents the substance in the image?

Accepted Answer

compound

Answer

element

Answer

mixture

Answer

mixture of compounds

Question 34

Strontium phosphate, Sr₃(PO₄)₂, is a crystalline substance used in medicine and industry. How many phosphorus atoms are represented in the formula for this compound?

Accepted Answer

2

Answer

3

Answer

4

Answer

8

Question 35

The table shows the chemical formulas of four substances. Which substances have the same number of carbon atoms?

Accepted Answer

substances 1 and 3

Answer

substances 1 and 2

Answer

substances 2, 3, and 4

Answer

substances 2 and 3 only

Question 36

Which of these formulas contain equal numbers of nitrogen atoms?

Accepted Answer

Formulas I, II, and V

Answer

Formulas I and III

Answer

Formulas I and IV

Answer

Formulas II and III

Question 37

This equation represents a chemical reaction that occurs in living cells. How many atoms are represented in this chemical equation?

Accepted Answer

36

Answer

6

Answer

12

Answer

24

Question 38

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

Accepted Answer

H2SO4

Answer

H3PO4

Answer

HClO3

Answer

H2O

Question 39

The chemical formula for sodium sulfate is Na₂SO₄. How many sulfur atoms are in the formula for sodium sulfate?

Accepted Answer

1

Answer

2

Answer

6

Answer

7

Question 40

Serotonin is a chemical substance that acts as a neurotransmitter. It helps replay messages in the human brain. The formula for one molecule of serotonin is C₁₀H₁₂N₂O. How many atoms are in one molecule of serotonin?

Accepted Answer

25

Answer

4

Answer

15

Answer

24

Question 41

Which information could a student determine from only the chemical formula of a protein?

Accepted Answer

the number of atoms of each element in the protein

Answer

the color of the protein

Answer

the number of molecules in each sequence that makes up a protein

Answer

the physical arrangement of atoms in the structure of the protein

Question 42

How many atoms of oxygen are in a molecule of glucose (C₆H₁₂O₆)?

Accepted Answer

6

Answer

3

Answer

24

Answer

1

Question 43

A student obtains two strips of magnesium, Mg, ribbon that are each 3 cm long. One strip of magnesium is placed in a test tube containing 5 mL of water, and the other strip is placed in a test tube containing 5 mL of hydrochloric acid, HCl. Both liquids area at room temperature. The student's observations are recorded in the table. Which statement is not supported by the students' observations?

Accepted Answer

The substances in both test tubes are reactive only as high temperatures.

Answer

A chemical reaction takes place between magnesium and hydrochloric acid.

Answer

A gas is released in Test Tube 2.

Answer

Energy is released in the reaction involving hydrochloric acid.

Question 44

A scientist performed four investigations using eight different liquids. In each investigation, the scientist combined two of the liquids under a fume hood and recorded observations in the table. In which investigation is it least likely that the liquids reacted chemically?

Accepted Answer

3

Answer

1

Answer

2

Answer

4

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