# Balancing Chemical Equations Quiz Questions And Answers

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With 11 years of urban teaching, Daniel excels as a STEM club teacher, demonstrating expertise in curriculum design, differentiated instruction for IEPs, and adept use of Google Classroom. His commitment to education shines through in his impactful contributions to STEM learning. Daniel holds a MSEd in Science Education from The City College of New York and a BA in History from Binghamton University. With certifications in Special Education and Biology, he is dedicated to curriculum development and enhancing educational experiences for students.
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Get ready for this balancing chemical equations quiz. When it comes to chemical reactions, there are some ways that you can identify the changes in the elements to check for physical changes or chemical changes. When it comes to chemical equations, there are some people who find it hard to balance them out and obtain the right solution. Are you one of them? If so, below are some questions to help you out?

• 1.

### ___ CH4 + ___O2 --> ___CO2 + ___H2O

• A.

1 2 1 2

• B.

2 1 2 1

• C.

3 1 2 4

• D.

1 2 3 4

• E.

4 3 1 2

A. 1 2 1 2
Explanation
The balanced equation for the combustion of methane (CH4) is CH4 + 2O2 --> CO2 + 2H2O. This means that for every molecule of methane, you need two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water.

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• 2.

### _____NH3             -->           ______N2             +            ______H2

• A.

3 1 2

• B.

2 1 3

• C.

1 2 3

• D.

3 2 1

• E.

1 3 2

B. 2 1 3
Explanation
The given balanced chemical equation represents the reaction between ammonia (NH3) and yields nitrogen gas (N2) and hydrogen gas (H2). The coefficients in front of each compound represent the number of moles of each compound involved in the reaction. In this case, the coefficients are 2, 1, and 3 for NH3, N2, and H2, respectively. This means that for every 2 moles of ammonia, 1 mole of nitrogen gas and 3 moles of hydrogen gas are produced.

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• 3.

### ______NH3             -->           ______NH2            +            ______H2

• A.

2 1 3

• B.

2 3 1

• C.

3 1 2

• D.

1 3 2

• E.

None of these

E. None of these
Explanation
The chemical equation you provided is:

NH3--------->NH2+H2

To balance this equation, you need to ensure that the number of atoms of each element is the same on both sides of the arrow. Here's the balanced equation:

2NH3----------------->NH2+3H2
Now, there are two nitrogen atoms on the left side and two on the right side, and there are six hydrogen atoms on the right side (3 in NH2 and 3 in H2) which balances the six hydrogen atoms on the left side.

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• 4.

### One CH4 molecule needs two O2 molecules for all the carbon and hydrogen atoms to  properly to oxygen atoms while obeying the law of conservation of mass.

• A.

True

• B.

False

A. True
Explanation
In a chemical reaction, the reactants must combine in specific ratios to form the products. In the case of methane (CH4) reacting with oxygen (O2), the balanced equation is CH4 + 2O2 -> CO2 + 2H2O. This means that for every methane molecule, two oxygen molecules are needed to ensure that all the carbon and hydrogen atoms in methane are properly bonded to oxygen atoms in the products. Therefore, the statement is true.

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• 5.

### ______ C            +             ______ O2             -->            ______ CO2 Write the correct prefixes below

• A.

2 1 1

• B.

1 1 1

• C.

1 2 1

• D.

1 2 3

• E.

None of these

B. 1 1 1
Explanation
The correct answer is 1 1 1. This is because the chemical equation given in the question shows the reaction between a carbon molecule (C) and an oxygen molecule (O2) to form carbon dioxide (CO2). The numbers before each element represent the number of atoms of that element in the equation. In this case, there is 1 carbon atom (C), 1 oxygen atom (O), and 1 oxygen molecule (O2), which contains 2 oxygen atoms.

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• 6.

### ______ C  +  O         ______ CO2 = 1 2 3

• A.

True

• B.

False

B. False
Explanation
False. The chemical equation you provided is unbalanced:

C+O------------>CO2

To balance the equation, you need to ensure that the number of atoms of each element is the same on both sides of the arrow. Here's the balanced equation:

C+O2---------------->CO2
Now, there is one carbon atom on each side, and there are two oxygen atoms on each side, balancing the equation. Therefore, the statement is false (F) when considering the unbalanced equation, but it becomes true (T) after balancing.

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• 7.

### ______ CH­2O            +             ______ HCl             -->            ______ CH4O             +            ______ Cl2

• A.

2 1 1 1

• B.

1 1 2 1

• C.

1 1 1 2

• D.

1 2 1 1

D. 1 2 1 1
Explanation
The balanced chemical equation for the given reaction is 1 CH2O + 2 HCl -> 1 CH4O + 1 Cl2. This means that for every 1 molecule of CH2O and 2 molecules of HCl, 1 molecule of CH4O and 1 molecule of Cl2 are produced. The answer, 1 2 1 1, represents the stoichiometric coefficients of the reactants and products in the balanced equation.

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• 8.

### ______ H2S             +            ______ O2          -->             ______ H2O          +         ______ S

• A.

2 1 2 2

• B.

2 2 1 2

• C.

2 2 2 1

• D.

1 2 2 2

• E.

3 1 2 2

A. 2 1 2 2
Explanation
The balanced equation for the reaction is 2H2S + O2 --> 2H2O + 2S. This means that for every 2 molecules of H2S and 1 molecule of O2, 2 molecules of H2O and 2 molecules of S are produced. Therefore, the correct answer is 2 1 2 2, indicating the number of molecules for each reactant and product in the balanced equation.

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• 9.

### What law says we must have balanced chemical equations?

• A.

The law of constant attention

• B.

• C.

The second law of thermodynamics

• D.

The law of conservation of mass

• E.

The rule of law

D. The law of conservation of mass
Explanation
The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction, but can only be rearranged. This means that the total mass of the reactants must be equal to the total mass of the products in a balanced chemical equation. This law is essential in chemistry as it helps to ensure that chemical reactions are accurately represented and that the amount of each element is conserved throughout the reaction.

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• 10.

### What would happen if we did not follow the law of conservation of mass when taking apart and then putting together a car for repair?

• A.

We would have extra pieces left over at the end.

• B.

Something would fall off the car soon enough.

• C.

A fuel leak might leave a trail of gasoline along the highway.

• D.

The car might blow up.

• E.

All of the above.

E. All of the above.
Explanation
If we did not follow the law of conservation of mass when taking apart and then putting together a car for repair, all of the above consequences would occur. Not conserving mass means that we would not properly account for all the parts and materials of the car, resulting in extra pieces left over at the end. This could lead to something falling off the car soon enough. Additionally, not properly handling the fuel system during repair could cause a fuel leak, leaving a trail of gasoline along the highway. Finally, if the car is not reassembled correctly, there is a risk of a major malfunction or explosion, causing the car to blow up.

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Daniel P |MSEd, Science |
Science Education
With 11 years of urban teaching, Daniel excels as a STEM club teacher, demonstrating expertise in curriculum design, differentiated instruction for IEPs, and adept use of Google Classroom. His commitment to education shines through in his impactful contributions to STEM learning. Daniel holds a MSEd in Science Education from The City College of New York and a BA in History from Binghamton University. With certifications in Special Education and Biology, he is dedicated to curriculum development and enhancing educational experiences for students.

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