Beane Unit 5 Chemistry Test
Questions and Answers
- 1.
What is the molar mass of water?
- A.
18
- B.
18.02
- C.
17.01
- D.
16
Correct Answer
B. 18.02Explanation
The molar mass of water is 18.02. Molar mass is the mass of one mole of a substance, and in the case of water, it is calculated by adding the atomic masses of two hydrogen atoms (1.01 g/mol each) and one oxygen atom (16.00 g/mol). Therefore, the molar mass of water is 2(1.01 g/mol) + 16.00 g/mol = 18.02 g/mol.Rate this question:
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- 2.
What is the value used for Avogadro’s number?
- A.
6.0
- B.
6.02
- C.
6.02 x10^23
- D.
6.02 x 10^32
Correct Answer
C. 6.02 x10^23Explanation
Avogadro's number is a fundamental constant in chemistry and physics that represents the number of atoms, molecules, or particles in one mole of a substance. The value used for Avogadro's number is 6.02 x 10^23, which means that one mole of any substance contains 6.02 x 10^23 atoms or molecules. This value is derived from experimental measurements and is widely accepted in scientific calculations and equations.Rate this question:
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- 3.
Which of the following compounds has a formula with no subscripts?
- A.
Nitrogen dioxide
- B.
Aluminum phosphate
- C.
Sodium hydroxide
- D.
Lithium nitrate
Correct Answer
C. Sodium hydroxideExplanation
Sodium hydroxide has a formula with no subscripts because it consists of only one sodium atom and one hydroxide ion. The sodium atom has a +1 charge, while the hydroxide ion has a -1 charge. To balance the charges, only one of each is needed, resulting in the formula NaOH.Rate this question:
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- 4.
A compound is found to contain 46.66% nitrogen and 53.34 % oxygen, what is the empirical formula?
- A.
![Beane Unit 5 Chemistry Test - Quiz]()
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
![Beane Unit 5 Chemistry Test - Quiz]()
Correct Answer
B.Explanation
The empirical formula of the compound can be determined by converting the percentages of nitrogen and oxygen into moles. Assuming a 100g sample, there would be 46.66g of nitrogen and 53.34g of oxygen in the compound. Using the molar masses of nitrogen (14.01 g/mol) and oxygen (16.00 g/mol), we can calculate the moles of each element. The ratio of moles of nitrogen to moles of oxygen is approximately 2:3. Therefore, the empirical formula of the compound is N2O3.Rate this question:
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- 5.
The molar mass for copper(II) sulfate pentahydrate is
- A.
159.6 g/mol
- B.
149.6 g/mol
- C.
259.6 g/mol
- D.
249.6 g/mol
Correct Answer
D. 249.6 g/molExplanation
The molar mass of copper(II) sulfate pentahydrate can be calculated by adding up the atomic masses of all the elements present in the compound. Copper has an atomic mass of 63.55 g/mol, sulfur has an atomic mass of 32.06 g/mol, oxygen has an atomic mass of 16.00 g/mol, and hydrogen has an atomic mass of 1.01 g/mol. Since there are five water molecules (H2O) in the compound, we need to multiply the atomic mass of water (18.02 g/mol) by 5. Adding up all these atomic masses gives a molar mass of 249.6 g/mol for copper(II) sulfate pentahydrate.Rate this question:
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- 6.
A substance has an empirical formula of . If the molar mass is 90 g/mol, what is the molecular formula?
- A.
![Beane Unit 5 Chemistry Test - Quiz]()
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
![Beane Unit 5 Chemistry Test - Quiz]()
Correct Answer
C. -
- 7.
Calculate the number of moles in 8.0 g of sodium hydroxide, NaOH.
- A.
.05
- B.
.10
- C.
.15
- D.
.20
Correct Answer
D. .20Explanation
The correct answer is .20. To calculate the number of moles, we need to use the molar mass of sodium hydroxide. The molar mass of NaOH is 22.99 + 16.00 + 1.01 = 40.00 g/mol. We can use the formula: moles = mass/molar mass. Plugging in the values, we get moles = 8.0 g / 40.00 g/mol = 0.20 mol.Rate this question:
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- 8.
In the following formula what is the substance that is reduced?
- A.
Al
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
Cu
Correct Answer
D. CuExplanation
In the given formula, Cu is the substance that is reduced. Reduction is a chemical reaction in which a substance gains electrons. In this case, Cu is undergoing reduction, meaning it is gaining electrons and being reduced to a lower oxidation state.Rate this question:
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- 9.
In the following formula what is the substance that is oxidized?
- A.
Al
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
Cu
Correct Answer
C.Explanation
The substance that is oxidized in the given formula is Al (aluminum).Rate this question:
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- 10.
In the following formula what is the substance that is reducing agent?
- A.
Al
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
Cu
Correct Answer
A. AlExplanation
Aluminum (Al) is the substance that acts as a reducing agent in the given formula. A reducing agent is a substance that donates electrons to another substance, causing it to be reduced. In this case, Al is donating electrons to another substance, causing it to be reduced.Rate this question:
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- 11.
In the following formula what is the substance that is oxidizing agent?
- A.
Al
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
Cu
Correct Answer
B.Explanation
The substance that is the oxidizing agent in the given formula is Cu.Rate this question:
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- 12.
What type of reaction is this?
- A.
Synthesis
- B.
Decomposition
- C.
Single replacement
- D.
Double replacement
Correct Answer
C. Single replacementExplanation
A single replacement reaction, also known as a substitution reaction, occurs when one element replaces another element in a compound. In this type of reaction, a more reactive element displaces a less reactive element in a compound, resulting in the formation of a new compound. This can be represented by the general equation A + BC → AC + B, where A is the more reactive element and B is the less reactive element.Rate this question:
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- 13.
What are the correct coefficients for the following equation?
- A.
2, 4, 4, 2
- B.
1, 2, 3, 1
- C.
1, 2, 2, 1
Correct Answer
C. 1, 2, 2, 1Explanation
The correct coefficients for the equation are 1, 2, 2, 1.Rate this question:
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- 14.
When the above equation is balanced, what is the coefficient for nickle (III) oxide?
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
A. 1Explanation
In a balanced chemical equation, the coefficients represent the number of molecules or atoms of each substance involved in the reaction. In this equation, the coefficient for nickel (III) oxide is 1, indicating that there is only one molecule of nickel (III) oxide involved in the reaction.Rate this question:
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- 15.
What kind of reaction does the above equation represent?
- A.
Synthesis
- B.
Decomposition
- C.
Single replacement
- D.
Double replacement
Correct Answer
D. Double replacementExplanation
The given equation represents a double replacement reaction. In a double replacement reaction, the cations and anions of two different compounds switch places, resulting in the formation of two new compounds. This process typically occurs when the reactants are in an aqueous solution and precipitates or gases are formed as products.Rate this question:
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- 16.
What are the reactants in the following equation? H2 + O2 → 2H2O
- A.
Hydrogen
- B.
Oxygen
- C.
Water
- D.
Hydrogen and Oxygen
Correct Answer
D. Hydrogen and OxygenExplanation
The reactants in the given equation are hydrogen and oxygen.Rate this question:
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- 17.
Which is the balanced equation for zinc added to sulfuric acid producing hydrogen gas and zinc sulfate?
- A.
![Beane Unit 5 Chemistry Test - Quiz]()
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
![Beane Unit 5 Chemistry Test - Quiz]()
Correct Answer
D. -
- 18.
What is the percent of oxygen in Fe2(SO4)3?
- A.
48%
- B.
31%
- C.
35%
- D.
100%
Correct Answer
A. 48%Explanation
The percent of oxygen in Fe2(SO4)3 can be calculated by finding the molar mass of oxygen in the compound and dividing it by the molar mass of the entire compound. In Fe2(SO4)3, there are 12 oxygen atoms with a molar mass of 16 g/mol each, giving a total mass of 192 g/mol. The molar mass of the entire compound is 399.88 g/mol. Dividing 192 g/mol by 399.88 g/mol and multiplying by 100 gives a result of approximately 48%. Therefore, the correct answer is 48%.Rate this question:
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- 19.
How many moles are 345 g of Na?
- A.
5.73 mol
- B.
15.0 mol
- C.
7930 mol
- D.
9.03 mol
Correct Answer
B. 15.0 molExplanation
The molar mass of Na (sodium) is 22.99 g/mol. To find the number of moles, we divide the given mass (345 g) by the molar mass of Na. 345 g / 22.99 g/mol = 15.0 mol. Therefore, 345 g of Na is equal to 15.0 moles.Rate this question:
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- 20.
Propane, C3H8 (g), burns in oxygen to form carbon dioxide and water. Which equation correctly shows this reaction?
- A.
![Beane Unit 5 Chemistry Test - Quiz]()
- B.
![Beane Unit 5 Chemistry Test - Quiz]()
- C.
![Beane Unit 5 Chemistry Test - Quiz]()
- D.
![Beane Unit 5 Chemistry Test - Quiz]()
Correct Answer
B.Explanation
The correct equation for the combustion of propane in oxygen is C3H8 + 5O2 → 3CO2 + 4H2O. This equation shows that one molecule of propane reacts with five molecules of oxygen to produce three molecules of carbon dioxide and four molecules of water.Rate this question:
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- 21.
In which situation is a chemical reaction occurring?
- A.
Salt dissolving in water
- B.
A nail rusting
- C.
Ice melting
- D.
A glass window breaking
Correct Answer
B. A nail rustingExplanation
A chemical reaction is occurring when a nail rusts. Rusting is a chemical process that involves the reaction of iron with oxygen and water, resulting in the formation of iron oxide. This process is an example of oxidation, where the iron atoms lose electrons and undergo a chemical change. In contrast, salt dissolving in water, ice melting, and a glass window breaking are physical changes rather than chemical reactions.Rate this question:
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- 22.
Fossil fuels that contain carbon, such as coal, petroleum and natural gas, combine with oxygen to produce carbon dioxide gas and energy often in the form of heat. These processes are example of which type of reactions?
- A.
Endothermic reactions
- B.
Metabolic reactions
- C.
Replacement reactions
- D.
Exothermic reaction
Correct Answer
D. Exothermic reactionExplanation
Fossil fuels, like coal, petroleum, and natural gas, undergo a reaction with oxygen where they combine to produce carbon dioxide gas and energy, usually in the form of heat. This type of reaction is known as an exothermic reaction because it releases energy in the form of heat.Rate this question:
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Current Version
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Mar 22, 2023Quiz Edited by
ProProfs Editorial Team -
Feb 12, 2014Quiz Created by
Andrew Beane
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