Use the equation to answer the question.

If you change the 2 in front of 2 O2
to a 3, what will be the change in the results on the right side of the equation?

(1 point)
Responses

There are now 3 CO2
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 3 H2O
molecules.
There are now 3 cap h sub 2 cap o molecules.

Nothing changes in the equation.
Nothing changes in the equation.
Question 2
Which statement comparing ionic and covalent bonds is correct?(1 point)
Responses

The difference between electronegativities is greater for atoms in covalent bonds than for atoms in ionic bonds.
The difference between electronegativities is greater for atoms in covalent bonds than for atoms in ionic bonds.

Elements in Group IA are more likely to form covalent bonds than ionic bonds with other atoms.
Elements in Group IA are more likely to form covalent bonds than ionic bonds with other atoms.

More electrons are transferred to form covalent bonds than ionic bonds.
More electrons are transferred to form covalent bonds than ionic bonds.

Covalent bonds tend to be less polar than ionic bonds.
Covalent bonds tend to be less polar than ionic bonds.
Question 3
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

PH3
PH 3

MgBr
MgBr

KCl2
KCl 2

SiO
SiO
Question 4
Which type of reaction is this?

Zn + 2HCl → ZnCl2 + H2

(1 point)
Responses

ionic
ionic

combustion
combustion

replacement
replacement

electronegative
electronegative
Question 5
Two carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2). How would each carbon atom in acetylene bond?

(2 points)
Responses

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.

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 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.
Question 6
Which option shows a correctly balanced chemical equation?

H2SO4 + HI → H2S + I2 + H2O

(2 points)
Responses

H2SO4 + HI → H2S + I2 + H2O
H 2 SO 4 + HI → H 2 S + I 2 + H 2 O

H2SO4 + 8HI → H2S + 4I2 + 4H2O
H 2 SO 4 + 8HI → H 2 S + 4I 2 + 4H 2 O

H2SO4 + 8HI → H2S + 8I2 + 4H2O
H 2 SO 4 + 8HI → H 2 S + 8I 2 + 4H 2 O

2H2SO4 + 2HI → 2H2S + I2 + 4H2O
2H 2 SO 4 + 2HI → 2H 2 S + I 2 + 4H 2 O
Question 7
Which numbers balance this equation?

4NaCl + 2SO2 + _____H2O + _____O2 → _____Na2SO4 + 4HCl

(2 points)
Responses

1, 2, 4
1, 2, 4

1, 2, 2
1, 2, 2

2, 1, 4
2, 1, 4

2, 1, 2
2, 1, 2
Question 8
Which statement describes the bonds in nitrate (NO3-)?

(2 points)
Responses

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

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

Nitrogen and oxygen have an electronegativity difference of 0.50.5, so the bond is nonpolar covalent.
Nitrogen and oxygen have an electronegativity difference of 0.50.5, so the bond is nonpolar covalent.

Nitrogen and oxygen have an electronegativity difference of 0.50.5, so the bond is ionic.
Nitrogen and oxygen have an electronegativity difference of 0.50.5, so the bond is ionic.
Question 9
When table salt forms, which action occurs between the reacting elements?(1 point)
Responses

Sodium shares an electron with chlorine.
Sodium shares an electron with chlorine.

Chlorine exchanges an electron with sodium.
Chlorine exchanges an electron with sodium.

Sodium donates an electron to chlorine.
Sodium donates an electron to chlorine.

Chlorine donates an electron to sodium.
Chlorine donates an electron to sodium.
Question 10
Which element gains two electrons to fill its outermost energy level?

(1 point)
Responses

fluorine (F)
fluorine (F)

lithium (Li)
lithium (Li)

magnesium (Mg)
magnesium (Mg)

selenium (Se)
selenium (Se)
Question 11
Which characteristic do electronegativity differences indicate about reactions between atoms?(1 point)
Responses

bond type
bond type

bond number
bond number

compound energy storage
compound energy storage

valence electron number
valence electron number
Question 12
Use the electronegativity and valence electron information to answer the question.

H electronegativity: 2.2
H valence electrons: 1
C electronegativity: 2.55
C valence electrons: 4
O electronegativity: 3.44
O valence electrons: 6
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?

(2 points)
Responses

eight
eight

six
six

three
three

five
five
Question 13
Which element is most likely to react with Br?

(1 point)
Responses

Ar
Ar

Sr
Sr

O
O

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

analyte
analyte

indicator
indicator

titrant
titrant

burette
burette
Skip to navigation

1 answer

Here are the answers to your questions:

Question 1

If you change the 2 in front of 2 O2 to a 3, what will be the change in the results on the right side of the equation?

  • Response: There is an extra O2 molecule left over. (This also means that there would be an increase in other products like CO2 or H2O depending on the original equation.)

Question 2

Which statement comparing ionic and covalent bonds is correct?

  • Response: Covalent bonds tend to be less polar than ionic bonds.

Question 3

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?

  • Response: PH3 (because phosphorus is in Group 15 and can form a stable molecule with hydrogen)

Question 4

Which type of reaction is this? Zn + 2HCl → ZnCl2 + H2

  • Response: replacement

Question 5

How would each carbon atom in acetylene bond?

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

Question 6

Which option shows a correctly balanced chemical equation? H2SO4 + HI → H2S + I2 + H2O

  • Response: H2SO4 + 8HI → H2S + 4I2 + 4H2O

Question 7

Which numbers balance this equation? 4NaCl + 2SO2 + _____H2O + _____O2 → _____Na2SO4 + 4HCl

  • Response: 2, 1, 4

Question 8

Which statement describes the bonds in nitrate (NO3-)?

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

Question 9

When table salt forms, which action occurs between the reacting elements?

  • Response: Sodium donates an electron to chlorine.

Question 10

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

  • Response: Selenium (Se)

Question 11

Which characteristic do electronegativity differences indicate about reactions between atoms?

  • Response: bond type

Question 12

How many bonds formed in H2CO3?

  • Response: five (There are two H–O bonds and one C=O bond, and counting the resonance structure, there can be five effective bonds.)

Question 13

Which element is most likely to react with Br?

  • Response: K (Potassium is an alkali metal that is likely to react with halogens like bromine.)

Question 14

Which term refers to a substance that changes color when there is a certain concentration of hydrogen ions in a solution?

  • Response: indicator

If you have further questions or need clarification on any topic, feel free to ask!