Topic 1 Topic 2 Topic 3 Topic 4 Topic 5

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20 20 20 20 20

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40 40 40 40 40

50 50 50 50 50

Question 1 - 10

Oxygen gas is written as O2 in chemical equations. What term is used to describe the “2” in this formula?

A. product B. coefficient

C. catalyst D. subscript

Answer 1 – 10

D. subscript

A subscript is the small number below an element

Question 1 - 20

What term is used to describe the “4” in the expression 4Ca(NO3)2?

A. coefficient B. formula

C. subscript D. symbol

Answer 1 – 20

A. coefficient

A coefficient is the big number in front

Question 1 - 30

Which of the following types of reactions is the opposite of a synthesis reaction?

A. displacement B. reversible

C. combustion D. decomposition

Answer 1 – 30

D. decomposition

Decomposition (breaking apart) is the opposite of synthesis (putting together)

Question 1 - 40

Which of the following processes is endothermic?

A. burning wood B. exploding dynamite

C. melting ice D. freezing water

Answer 1 – 40

• C. melting ice

• Melting ice is endothermic because you add heat to melt the ice

Question 1 - 50

Which diagram below shows the correct location of the reactants and products of a chemical reaction?

A. reactants products

B. products reactants

Answer 1 – 50

• A. reactants products

Reactants are before the arrow; products after because they are what’s produced

Question 2 - 10

When a chemical equation is balanced it shows that

A. mass is conserved

B. energy is conserved

C. nothing is conserved

Answer 2 – 10

• A. mass is conserved

• A balanced equation shows that mass is conserved

Question 2 - 20

In a combustion reaction, oxygen gas is a

A. reactant B. product C. neither

Answer 2 – 20

• A. reactant

• Oxygen gas is a reactant is a combustion reaction

Question 2 - 30

Food preservatives are added to slow down the chemical reaction that makes food go bad. In this case, food preservatives are

A. catalysts

B. products

C. inhibitors

Answer 2 – 30

C. inhibitors

Food preservatives are inhibitors because they slow down a chemical reaction of the food aging

Question 2 - 40

A substance that produces hydrogen ions in solution is a(n)

A. acid B. base

Answer 2 – 40

A. acid

An acid produces Hydrogen ions

Question 2 - 50

The sour taste of citrus fruits is caused by the presence of __________ in these foods.

A. acid B. base

Answer 2 – 50

A. acid

Acids taste sour

Question 3 - 10

A substance that breaks apart completely in a solution is called a

A. strong acid/base

B. weak acid/ base

C. dilute acid/base

Answer 3 – 10

A. strong acid/base

A strong acid/base breaks apart completely

Question 3 - 20

On the pH scale, a pH of 7 indicates that something is

A. acidic B. basic C. neutral

Answer 3 – 20

C. neutral

pH of 7 is neutral

Question 3 - 30

The pH of lemon juice is most likely close to

A. 7 B. 3 C. 10 D. 11

Answer 3 – 30

B. 3

Lemon juice is an acid so its pH is below 7

Question 3 - 40

Antacids work because they __________ excess stomach acid.

A. contain B. neutralize

C. acidify D. concentrate

Answer 3 – 40

B. neutralize

Antacids work against stomach acid to neutralize acid

Question 3 - 50

A solution with a bitter taste and a slippery feel is most likely

A. an acid B. a base

C. salt D. a chemical

Answer 3 – 50

B. a base

Bases taste bitter and are slippery

Question 4 - 10

When you wash your hands with soap you are using a

A. buffer B. acid

C. base D. indicator

Answer 4 – 10

C. base

Soap is a base (slippery)

Question 4 - 20

Balance the equation below:

______ H2 + ______ O2 _______ H2O

Answer 4 – 20

_2_H2 + ___1___ O2 __2__ H2O

Question 4 - 30

• Balance the equation:

• _______P + ______ O2 _______ P4O10

Answer 4 – 30

• __4__P + _5__ O2 ___1____ P4O10

Question 4 - 40

Balance the equation:

_______Ag2O ______Ag + ______O2

Answer 4 – 40

___2____Ag2O ___4___Ag + ___1__O2

Question 4 - 50

• Balance the equation:

____K + ____MgBr _____KBr +_____Mg

Answer 4 – 50

1 K + 1 MgBr 1 KBr + 1 Mg

Question 5 - 10

• Balance the equation:

• ______ H2O + ______O2 _______ H2O2

Answer 5 – 10

___2___ H2O + __1___O2 __ 2 ___ H2O2

Question 5 - 20

Type of chemical reaction?

C10H8 + 12 O2 → 10 CO2 + 4 H2O

Answer 5 – 20

Combustion- combines with oxygen and makes carbon dioxide and water

Question 5 - 30

• Type of reaction?

• NaCl + AgNO3 → NaNO3 + AgCl

Answer 5 – 30

Double displacement-each element in the compound switches and forms a new compound

Question 5 - 40

• Reaction type?

• Zn + 2 HCl → ZnCl2 + H2

Answer 5 – 40

• Single displacement-one element in the compound is replaced. One element is by itself

Question 5 - 50

• Reaction type?

• 8 Fe + S8 → 8 FeS

Answer 5 – 50

Synthesis-two elements form a compound

Question 6-60

What is the reaction type?

2 H2O → 2 H2 + O2

Answer 6-60

Decomposition-a compound breaks apart into separate elements