correct answers only

Question

Question 1
A)
Use the equation to answer the question.

CH4 + 2O2 → CO2 + 2H2O

If you change2O2
to a 3O2
, what will be the change in the results on the right side of the equation.

(1 point)
Responses

Nothing changes in the equation.
Nothing changes in the equation.

There are now 3CO2
molecules.
There are now 3 cap c cap o sub 2 molecules.

There is an extra O2
molecule left over.
There is an extra cap o sub 2 molecule left over.

There are now 3H2O
molecules.
There are now 3 cap h sub 2 cap o molecules.
Question 2
A)Which of the following statements accurately compares ionic and covalent bonds?(1 point)
Responses

More electrons are transferred in the formation of covalent bonds compared to ionic bonds.
More electrons are transferred in the formation of covalent bonds compared to ionic bonds.

Atoms in covalent bonds have a greater difference in electronegativity than atoms in ionic bonds.
Atoms in covalent bonds have a greater difference in electronegativity than atoms in ionic bonds.

Covalent bonds generally have less polarity than ionic bonds.
Covalent bonds generally have less polarity than ionic bonds.

Elements in Group IA are more likely to form covalent bonds rather than ionic bonds with other atoms.
Elements in Group IA are more likely to form covalent bonds rather than ionic bonds with other atoms.
Question 3
A)
Use the periodic table to answer the question.

periodic table

































A chemical reaction produces a molecule in which all of the atoms have a stable configuration. Which molecule could be the product of the reaction?

(1 point)
Responses

PH4
cap p cap h sub 4

SiO5
cap s i cap o sub 5

CaBr2
cap c A cap b r sub 2

NaCl2
cap n A cap c l sub 2
Question 4
A)
Use the reaction to answer the question.

Zn+2HCl→ZnCl2+H2

Which type of reaction is this?

(1 point)
Responses

electronegative
electronegative

ionic
ionic

combustion
combustion

single-replacement
single-replacement
Question 5
A)
Use the periodic table to answer the question.

Two carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2
). How would each carbon atom in acetylene bond?

(1 point)
Responses

Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.
Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.

Each carbon atom would share one pair of electrons with the other carbon atom and two pairs with each hydrogen atom.
Each carbon atom would share one pair of electrons with the other carbon atom and two pairs with each hydrogen atom.

Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.
Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.

Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
Question 6
A)Which of the following equations if correctly balanced?(1 point)
Responses

C8H8+3O2→3CO2+4H2O
cap c sub 8 cap h sub 8 plus 3 cap o sub 2 rightarrow 3 cap c cap o sub 2 plus 4 cap h sub 2 cap o

C8H8+2O2→CO2+4H2O
C8H8+2O2→CO2+4H2O

C8H8+4O2→3CO2+3H2O
cap c sub 8 cap h sub 8 plus 4 cap o sub 2 rightarrow 3 cap c cap o sub 2 plus 3 cap h sub 2 cap o

C8H8+5O2→3CO2+4H2O
cap c sub 8 cap h sub 8 plus 5 cap o sub 2 rightarrow 3 cap c cap o sub 2 plus 4 cap h sub 2 cap o
Question 7
A)Use the equation to answer the question.(1 point)
4NaCl+2SO2+4H2O+

O2→

Na2SO4+4HCl

Select the numbers from the drop down box that would balance this equation.

Question 8
A)
Use the electronegativity periodic table to answer the question.

Which statement describes the bonds in carbon dioxide (CO2
)?

(1 point)
Responses

Carbon and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.
Carbon and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.

Carbon and oxygen have an electronegativity difference of 1.0, so the bond is polar covalent, with oxygen pulling the electrons toward it.
Carbon and oxygen have an electronegativity difference of 1.0, so the bond is polar covalent, with oxygen pulling the electrons toward it.

Carbon and oxygen have an electronegativity difference of 0.5, so the bond is nonpolar covalent, with oxygen pulling the electrons toward it.
Carbon and oxygen have an electronegativity difference of 0.5, so the bond is nonpolar covalent, with oxygen pulling the electrons toward it.

Carbon and oxygen have an electronegativity difference of 0.5, so the bond is ionic, with oxygen pulling the electrons toward it.
Carbon and oxygen have an electronegativity difference of 0.5, so the bond is ionic, with oxygen pulling the electrons toward it.
Question 9
A)When potassium salt (KCl) forms, which action occurs between the reacting elements?(1 point)
Responses

Nothing happens.
Nothing happens.

Potassium donates an electron to chlorine.
Potassium donates an electron to chlorine.

Chlorine donates an electron to potassium.
Chlorine donates an electron to potassium.

Potassium shares an electron with chlorine.
Potassium shares an electron with chlorine.
Question 10
A)
Use the periodic table to answer the question.

Which element gains three electrons to fill its outermost energy level?

(1 point)
Responses

Calcium (Ca)
Calcium (Ca)

Nitrogen (N)
Nitrogen (N)

Neon (Ne)
Neon (Ne)

Sulfur (S)
Sulfur (S)
Question 11
A)Which characteristic do electronegativity differences indicate about reactions between atoms?(1 point)
Responses

bond number
bond number

bond type
bond type

valence electron number
valence electron number

compound energy storage
compound energy storage
Question 12
A)
Use the electronegativity and valence electron information in the table to answer the question.

Element Valence Electrons Electronegativity
Hydrogen 1 2.2
Carbon 4 2.55
Oxygen 6 3.44
Chemical weathering over hundreds of thousands of years formed modern caves. One form of chemical weathering occurs when carbon dioxide reacts with water to produce carbonic acid (H2CO3
). How many bonds formed in H2CO3
?

(1 point)
Responses

five
five

eight
eight

three
three

six
six
Question 13
A)
Use the electronegativity periodic table to answer the question.

Which element is most likely to react with Cl?

(1 point)
Responses

Br
Br

Si
Si

S
S

Rb
Rb
Question 14
A)Which term refers to a substance that changes color when there is a certain concentration of hydrogen ions in a solution?(1 point)
Responses

titrant
titrant

burette
burette

indicator
indicator

analyte
analyte
Question 15
A)
Use the following chemical equation. (3 points)

H2+O2→2H2O

Using the drop down box selection to construct a statement that correctly supports the argument that the chemical equation shown violates the law of conservation of matter.

(3 points)
There are more
atoms on the
of the arrow than on the
.
Question 16
A)
Balance the following chemical equation. Drag the option from the list at the bottom to the correct spot. (4 points)



(4 points)
Put responses in the correct input to answer the question. Select a response, navigate to the desired input and insert the response. Responses can be selected and inserted using the space bar, enter key, left mouse button or touchpad. Responses can also be moved by dragging with a mouse.
2Ag2O→
Response areaAg+
Response areaO2
Question 17
A)Determine if the given equation if BALANCED or UNBALANCED. (5 points)(5 points)
BALANCED UNBALANCED
N2+3H2→2NH3

2C2H6+7O2→4CO2+5H2O

4ZnS+6O2→4ZnO+2SO2

2Fe2O3+3C→4Fe+3CO2

C3H8+5O2→3CO2+4H2O

Question 18
A)
Use the periodic table for the question provided. (4 points)

Methane (CH4
) is a gas that is found in small quantities in Earth's atmosphere. Select the correct responses that make the whole statement accurate.

(4 points)
The bonds in methane are
because hydrogen and carbon have
electronegativity. Carbon bonds with four hydrogen atoms because hydrogen has
valence electron(s) and carbons has
valence electrons; so carbon shares
valence electron(s) with each of the four hydrogen atoms to satisfy the necessary
valence electrons for carbon and
for hydrogen to become
​​​​​​​.

Answer 1

Here are the correct answers to your questions:

Question 1:

• Response: There is an extra O2 molecule left over.

Question 2:

• Response: Covalent bonds generally have less polarity than ionic bonds.

Question 3:

• Response: CaBr2 (It has a stable configuration as both calcium and bromine achieve noble gas configuration.)

Question 4:

• Response: single-replacement

Question 5:

• Response: Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.

Question 6:

• Response: C8H8 + 3O2 → 3CO2 + 4H2O

Question 7:

• Response: Unfortunately, I can't select from a dropdown as I cannot view or interact with it. Please provide the balancing numbers if specific options are available.

Question 8:

• Response: Carbon and oxygen have an electronegativity difference of 1.0, so the bond is polar covalent, with oxygen pulling the electrons toward it.

Question 9:

• Response: Potassium donates an electron to chlorine.

Question 10:

• Response: Nitrogen (N)

Question 11:

• Response: bond type

Question 12:

• Response: three

Question 13:

• Response: Rb

Question 14:

• Response: indicator

Question 15:

• Response: There are more atoms on the right of the arrow than on the left.

Question 16:

• Response: 2Ag + 1O2 (i.e., 2Ag2O → 4Ag + O2)

Question 17:

• BALANCED for N2 + 3H2 → 2NH3
• UNBALANCED for 2C2H6 + 7O2 → 4CO2 + 5H2O
• BALANCED for 4ZnS + 6O2 → 4ZnO + 2SO2
• UNBALANCED for 2Fe2O3 + 3C → 4Fe + 3CO2
• UNBALANCED for C3H8 + 5O2 → 3CO2 + 4H2O

Question 18:

• The bonds in methane are covalent because hydrogen and carbon have similar electronegativity. Carbon bonds with four hydrogen atoms because hydrogen has 1 valence electron(s) and carbon has 4 valence electrons; so carbon shares 1 valence electron(s) with each of the four hydrogen atoms to satisfy the necessary valence electrons for carbon and 2 for hydrogen to become stable.

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