Chemistry Semester 2 Midterm (3/28/2024)

Instructions

Answer each of the following question according to the directions. For the drag and drop questions, answer choices may be reused in the same question.

1

Identify the compound with ionic bonds.

1

To balance an equation ______________ must be placed in front of the compound(s) and or element(s).

1

Identify the compound with covalent bonds.

1

Which of the following contains BOTH ionic and covalent bonds?

1

What is the charge on the Cr ions in Cr2O3?

1

Calculate the molar mass of Al(C2H3O2)3.

1

How many moles of N2O4 are in 76.3 g N2O4? The molar mass of N2O4 is 92.02 g/mol.

4

How many atoms of oxygen are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g/mol.
 47.6 g x (1mol/_____________ ) x (__________ /1mol) x(______________________ ) = ______________________  

Other Answer Choices:

233.99 g

6.02 x 1023 atoms

1.10 x 1024 atoms

9 mol

4

Hydrazine, N2H4, and dinitrogen tetroxide, N2O4, react to form gaseous nitrogen and water. Which of these represents a properly balanced equation for this reaction?
______ N2H4 + ______ N2O4 --> ______ N2 + ______ H2O

Other Answer Choices:

1

3

2

4

1

When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs.
CH4 + 2O2 → CO2 + 2H2O
If 1 mole of methane reacts with 2 moles of oxygen, then

1

A balanced chemical equation reflects the idea that the mass of the products

1

A student heated a 10 g sample of a compound in an open container. A chemical reaction occurred. The mass of the sample was measured again and found to be less than before. Which of the following explains the change in mass of the sample?

6

The chemical equation below represents sulfur trioxide (SO3) in the atmosphere mixing with rainwater to form sulfuric acid (H2SO4), which is a major component of acid rain.
                                SO3(g) + H2O(l) --> H2SO4(l)
 How much H2SO4 is produced when 128.0 g of SO3 mixes with rainwater?
SO3: (1 x 32) + (3 x 16) =_________H2SO4: (2 x 1) + (1 x 32) + (4 x 16) = _________ 
Solution:
(__________  / _________)x _________ = __________  

Other Answer Choices:

80 g

128 g

98 g

157 g

1

The equation below represents a balanced chemical reaction:
2Mg(s) + O2(g) --> 2MgO(s)
How many moles of MgO are produced when 7.2 moles of O2 react with excess Mg?

1

What type of force holds ions together in salts such as CaF2?

1

Which of the following pairs of atoms is unlikely to form a compound?

1

Use the diagram to answer the following question.

How many bonds are made by each carbon atom in the molecule shown above?

1

Two elements in a molecule have the same electronegativity values. Which of the following most likely holds the elements together and why?

1

Which of the following are most directly involved in chemical bonding?

11

	Ionic Bond	Covalent Bond	Metallic Bond
Higher melting point
Lower melting point
Brittle and hard
Exists as solid, liquid, and gas at STP
Malleable and lustrous
Conductive as a solid
Poor conductor
Lattice made of positive and negative ions
Lattice of positive ions surrounded by sea of electrons
Shared electrons between two or more atoms

4

 ______ C5H12 +  ______ O2 --> ______ CO2 + ______ H2O 

Other Answer Choices:

5

8

6

1

6

For the reactions below, select the correct reaction type and drag it onto the equation.

Double Replacement
Single Replacement
Decomposition
Synthesis
Combustion

C2H4 + 3O2 --> 2CO2 + 2H2O

6

Place the items in order to show how to solve a grams to mole stoichiometry problem.

Write a balanced equation
Identify the mole ratios of the balanced equation
Identify the given and unknown substances
Calculate the molar mass of the given
Multiply by the mole ratio
Convert to moles by dividing by molar mass

Chemistry Semester 2 Midterm (3/28/2024)

Identify the compound with ionic bonds.

To balance an equation ______________ must be placed in front of the compound(s) and or element(s).

Identify the compound with covalent bonds.

Which of the following contains BOTH ionic and covalent bonds?

What is the charge on the Cr ions in Cr2O3?

Calculate the molar mass of Al(C2H3O2)3.

How many moles of N2O4 are in 76.3 g N2O4? The molar mass of N2O4 is 92.02 g/mol.

When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs. CH4 + 2O2 → CO2 + 2H2OIf 1 mole of methane reacts with 2 moles of oxygen, then

A balanced chemical equation reflects the idea that the mass of the products

A student heated a 10 g sample of a compound in an open container. A chemical reaction occurred. The mass of the sample was measured again and found to be less than before. Which of the following explains the change in mass of the sample?

The equation below represents a balanced chemical reaction: 2Mg(s) + O2(g) --> 2MgO(s)How many moles of MgO are produced when 7.2 moles of O2 react with excess Mg?

What type of force holds ions together in salts such as CaF2?

Which of the following pairs of atoms is unlikely to form a compound?

Use the diagram to answer the following question.How many bonds are made by each carbon atom in the molecule shown above?

Two elements in a molecule have the same electronegativity values. Which of the following most likely holds the elements together and why?

Which of the following are most directly involved in chemical bonding?

For the reactions below, select the correct reaction type and drag it onto the equation.

Place the items in order to show how to solve a grams to mole stoichiometry problem.

Identify the compound with ionic bonds.

To balance an equation ______________ must be placed in front of the compound(s) and or element(s).

Identify the compound with covalent bonds.

Which of the following contains BOTH ionic and covalent bonds?

What is the charge on the Cr ions in Cr2O3?

Calculate the molar mass of Al(C2H3O2)3.

How many moles of N2O4 are in 76.3 g N2O4? The molar mass of N2O4 is 92.02 g/mol.

When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs. CH4 + 2O2 → CO2 + 2H2OIf 1 mole of methane reacts with 2 moles of oxygen, then

A balanced chemical equation reflects the idea that the mass of the products

A student heated a 10 g sample of a compound in an open container. A chemical reaction occurred. The mass of the sample was measured again and found to be less than before. Which of the following explains the change in mass of the sample?

The equation below represents a balanced chemical reaction: 2Mg(s) + O2(g) --> 2MgO(s)How many moles of MgO are produced when 7.2 moles of O2 react with excess Mg?

What type of force holds ions together in salts such as CaF2?

Which of the following pairs of atoms is unlikely to form a compound?

Use the diagram to answer the following question.How many bonds are made by each carbon atom in the molecule shown above?

Two elements in a molecule have the same electronegativity values. Which of the following most likely holds the elements together and why?

Which of the following are most directly involved in chemical bonding?

For the reactions below, select the correct reaction type and drag it onto the equation.

Place the items in order to show how to solve a grams to mole stoichiometry problem.

When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs.
CH4 + 2O2 → CO2 + 2H2O
If 1 mole of methane reacts with 2 moles of oxygen, then

The equation below represents a balanced chemical reaction:
2Mg(s) + O2(g) --> 2MgO(s)
How many moles of MgO are produced when 7.2 moles of O2 react with excess Mg?

Use the diagram to answer the following question.

How many bonds are made by each carbon atom in the molecule shown above?

When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs.
CH4 + 2O2 → CO2 + 2H2O
If 1 mole of methane reacts with 2 moles of oxygen, then

The equation below represents a balanced chemical reaction:
2Mg(s) + O2(g) --> 2MgO(s)
How many moles of MgO are produced when 7.2 moles of O2 react with excess Mg?

Use the diagram to answer the following question.

How many bonds are made by each carbon atom in the molecule shown above?