General Chemistry Practice Test Questions With Answers
If you are looking for a good set of general chemistry practice questions with answers, take this test and enhance your chemistry knowledge. General chemistry deals with the basic concepts of chemistry, including atomic and molecular bonding theory, atomic structures, chemical reactions, and solutions. Do you really think you are good enough to solve all questions based on these concepts? Why don't you give this quiz a try and evaluate your knowledge? All the very best to you!
Questions and Answers
- 1.
Which of the following are representations of the same molecule?(i) CH3CH2CH2CH2CH2CH2(ii) CH3 CH2CH2CH2CH2CH3(iii) CH2CH2CH2 CH3 CH2CH3
- A.
Only (i) and (ii)
- B.
Only (i) and (iii)
- C.
Only (ii) and (iii)
- D.
All of them
Correct Answer
C. Only (ii) and (iii)Explanation
The correct answer is only (ii) and (iii) because both (ii) and (iii) have the same number and arrangement of atoms. In both representations, there are six carbon atoms in a row, with three hydrogen atoms attached to the first carbon and two hydrogen atoms attached to the last carbon. The only difference between (ii) and (iii) is the position of the three hydrogen atoms in the middle, but this does not affect the overall structure of the molecule. Therefore, (ii) and (iii) are representations of the same molecule.Rate this question:
-
- 2.
Which of the following explains why alkanes are called saturated hydrocarbons?
- A.
They contain the maximum possible number of hydrogen atoms
- B.
They are the most highly reactive organic compounds
- C.
They have dissolved to the maximum extent possible
- D.
They are good solvents
Correct Answer
A. They contain the maximum possible number of hydrogen atomsExplanation
Alkanes are called saturated hydrocarbons because they contain the maximum possible number of hydrogen atoms. In alkanes, all carbon atoms are bonded to four other atoms, either hydrogen or carbon. This results in each carbon atom being saturated with hydrogen atoms, meaning it has the maximum number of hydrogen atoms attached to it. This saturation with hydrogen atoms gives alkanes their stability and low reactivity compared to other organic compounds.Rate this question:
-
- 3.
Compounds which contain a carbon-carbon triple bond are classified as which of the following?
- A.
Arenes
- B.
Alkanes
- C.
Alkenes
- D.
Alkynes
Correct Answer
D. AlkynesExplanation
Compounds that contain a carbon-carbon triple bond are classified as alkynes. Alkynes are a type of hydrocarbon that have a triple bond between two carbon atoms. This triple bond gives alkynes unique properties and reactivity compared to other types of hydrocarbons. Alkenes, on the other hand, have a double bond between two carbon atoms, while alkanes do not have any double or triple bonds. Arenes are a separate class of compounds that contain a benzene ring structure. Therefore, the correct classification for compounds with a carbon-carbon triple bond is alkynes.Rate this question:
-
- 4.
In organic compounds a halogen atom can replace which of the following?
- A.
Hydrogen
- B.
Oxygen
- C.
Nitrogen
- D.
Carbon
Correct Answer
A. HydrogenExplanation
In organic compounds, a halogen atom can replace a hydrogen atom. This is because halogens have a similar electron configuration to hydrogen and can easily bond with carbon atoms to form stable organic compounds. Halogen substitution reactions are common in organic chemistry and are used to introduce halogen atoms into organic molecules.Rate this question:
-
- 5.
Which of the following is a gas at room temperature and pressure?
- A.
Hexane
- B.
Pentane
- C.
Butane
- D.
None of them
- E.
3-
Correct Answer
C. ButaneExplanation
Butane is a gas at room temperature and pressure. It has a boiling point of -1°C and a melting point of -138.3°C, which means it exists as a gas at typical room temperature and pressure conditions. Hexane and pentane are both liquids at room temperature and pressure, while "none of them" is incorrect as butane fits the criteria.Rate this question:
-
- 6.
What is the IUPAC name of: CH2CH2CH2CH3CH3CCH2CH3 CH2CH2CH3
- A.
3-methyl-3-propylheptane
- B.
2-ethyl-2-propylhexane
- C.
4-ethyl-4-methyloctane
- D.
None of these
Correct Answer
C. 4-ethyl-4-methyloctane -
- 7.
Which of the following is true when there is a single substituent on cyclohexane?
- A.
The substituent will prefer to be in the axial position
- B.
The substituent has no particular preference for either the axial or equatorial position
- C.
The situation will vary, depending on the identity of the substituent
- D.
The substituent will prefer to be in the equatorial position
Correct Answer
D. The substituent will prefer to be in the equatorial positionExplanation
When there is a single substituent on cyclohexane, the substituent will prefer to be in the equatorial position. This is because the axial position is less stable due to steric hindrance. Placing the substituent in the equatorial position allows for greater separation between the substituent and the other groups attached to the cyclohexane ring, reducing steric interactions and increasing stability. Therefore, the substituent will favor the equatorial position over the axial position.Rate this question:
-
- 8.
How many moles of oxygen are consumed by the complete combustion of one mole of propane, C3H8?
- A.
7
- B.
1
- C.
5
- D.
3
Correct Answer
C. 5Explanation
The complete combustion of propane, C3H8, produces carbon dioxide (CO2) and water (H2O). The balanced chemical equation for this reaction is: C3H8 + 5O2 -> 3CO2 + 4H2O. From the equation, we can see that for every mole of propane consumed, 5 moles of oxygen are required. Therefore, the correct answer is 5.Rate this question:
-
- 9.
Which of the following has the highest boiling point?
- A.
Hexane
- B.
Octane
- C.
Nonane
- D.
Heptane
Correct Answer
C. NonaneExplanation
Nonane has the highest boiling point among the given options. Boiling point is determined by the strength of intermolecular forces between molecules. Nonane has a larger number of carbon atoms compared to hexane, octane, and heptane, which results in stronger London dispersion forces. These forces require more energy to break, leading to a higher boiling point for nonane.Rate this question:
-
- 10.
In which of the following classes of organic compounds is an oxygen atom bonded to a hydrogen atom?
- A.
Alcohols
- B.
Aldehydes
- C.
Amines
- D.
All of these
Correct Answer
A. AlcoholsExplanation
Alcohols are a class of organic compounds where an oxygen atom is bonded to a hydrogen atom. This is because alcohols have a hydroxyl group (-OH) attached to a carbon atom. Aldehydes, on the other hand, have a carbonyl group (-CHO) instead of a hydroxyl group. Amines do not have any oxygen-hydrogen bonds, as they are compounds where a nitrogen atom is bonded to one or more carbon atoms. Therefore, the correct answer is alcohols.Rate this question:
-
- 11.
Which of the following is a constitutional isomer of butane, CH3(CH2)2CH3 ?
- A.
CH3CHCH3 CH3
- B.
CH3 CH2CH2CH3
- C.
CH3CH2CH2 CH3
- D.
None of these
Correct Answer
A. CH3CHCH3 CH3Explanation
A constitutional isomer is a compound that has the same molecular formula but a different arrangement of atoms. In this case, the given compound is butane (CH3(CH2)2CH3), which has four carbon atoms in a straight chain. The isomer CH3CHCH3, also known as 2-methylpropane or isobutane, has the same molecular formula but a different arrangement of atoms. It has a branched structure with a methyl group attached to the second carbon atom. Therefore, it is a constitutional isomer of butane.Rate this question:
-
- 12.
In which of the following types of reactions is sulfuric acid used as a catalyst?
- A.
Hydration
- B.
Hydrohalogenation
- C.
Halogenation
- D.
Hydrogenation
Correct Answer
A. HydrationExplanation
Sulfuric acid is used as a catalyst in the hydration reaction. In this type of reaction, water molecules are added to a compound, resulting in the formation of a new compound. Sulfuric acid helps to facilitate this reaction by providing a suitable environment for the reaction to occur, increasing the reaction rate without being consumed in the process.Rate this question:
-
- 13.
When listing the substituents in correct order, which of the following should not be ignored?
- A.
Iso
- B.
Sec-
- C.
Di-
- D.
None, all should be ignored
Correct Answer
A. IsoExplanation
When listing the substituents in correct order, the prefix "iso" should not be ignored. The prefix "iso" is used to indicate that the substituent is attached to a branch point in the carbon chain. It is important to include this prefix in the correct order to accurately describe the molecule's structure.Rate this question:
-
- 14.
Which of the following chemicals, when pure, will have different properties if it is synthesized in the laboratory than if it is obtained from a natural source?
- A.
Ethanol
- B.
Vitamin C
- C.
Taxol
- D.
None of these
Correct Answer
D. None of theseExplanation
The correct answer is "none of these" because all of the listed chemicals, ethanol, vitamin C, and taxol, will have the same properties regardless of whether they are synthesized in a laboratory or obtained from a natural source. The properties of a chemical compound are determined by its molecular structure, which remains the same regardless of its origin. Therefore, there would be no difference in the properties of these chemicals based on their source.Rate this question:
-
- 15.
Which isomer of pentane has the lowest boiling point?
- A.
2,2-dimethypropane
- B.
Pentane
- C.
2-methylbutane
- D.
None, they all have the same boiling point
Correct Answer
A. 2,2-dimethypropaneExplanation
2,2-dimethylpropane has the lowest boiling point among the given isomers of pentane. This is because 2,2-dimethylpropane is a branched isomer, which means it has a lower surface area compared to the other isomers. The boiling point of a compound is determined by the strength of intermolecular forces, such as van der Waals forces. Branched isomers have fewer points of contact between molecules, resulting in weaker intermolecular forces and a lower boiling point. Therefore, 2,2-dimethylpropane has the lowest boiling point among the given isomers of pentane.Rate this question:
-
- 16.
Compounds which contain a carbon-carbon double bond are classified as which of the following?
- A.
Alkanes
- B.
Alkynes
- C.
Arenes
- D.
Alkenes
Correct Answer
D. AlkenesExplanation
Compounds that contain a carbon-carbon double bond are classified as alkenes. Alkenes are unsaturated hydrocarbons that have at least one double bond between two carbon atoms. This double bond gives alkenes their characteristic reactivity and makes them different from alkanes, which only have single bonds between carbon atoms. Alkynes have triple bonds, while arenes are compounds that contain a benzene ring. Therefore, the correct classification for compounds with a carbon-carbon double bond is alkenes.Rate this question:
-
- 17.
Alkanes belong to which class of hydrocarbons?
- A.
Aromatic
- B.
Unsaturated
- C.
Saturated
- D.
Alkali
Correct Answer
C. SaturatedExplanation
Alkanes belong to the class of hydrocarbons known as saturated. This is because alkanes contain only single bonds between carbon atoms, resulting in a maximum number of hydrogen atoms bonded to each carbon atom. This arrangement of single bonds and maximum hydrogen atoms makes alkanes saturated with hydrogen, hence the classification.Rate this question:
-
- 18.
What is the IUPAC name of:
- A.
Isopropylpropylcyclohexane
- B.
1,1-dipropylcyclohexane
- C.
1-isopropyl-1-propylcyclohexane
- D.
None of these
Correct Answer
C. 1-isopropyl-1-propylcyclohexaneExplanation
The IUPAC name of the given compound is 1-isopropyl-1-propylcyclohexane. This is because the compound contains a cyclohexane ring with two substituents attached to it. The first substituent is an isopropyl group (CH3CH(CH3)CH2-) attached to the first carbon of the ring, and the second substituent is a propyl group (CH3CH2CH2-) attached to the first carbon of the ring as well. Therefore, the correct IUPAC name is 1-isopropyl-1-propylcyclohexane.Rate this question:
-
- 19.
Which of the following is the most characteristic reaction of alkenes?
- A.
Addition
- B.
Oxidation
- C.
Reduction
- D.
Substitution
Correct Answer
A. AdditionExplanation
The most characteristic reaction of alkenes is addition. Alkenes have a double bond between carbon atoms, which makes them highly reactive. Addition reactions involve breaking the double bond and adding new atoms or groups to the carbon atoms. This can result in the formation of new compounds with different properties. Oxidation, reduction, and substitution reactions can also occur with alkenes, but addition reactions are the most common and distinctive.Rate this question:
-
- 20.
In organic compounds which of the following elements normally forms three covalent bonds?
- A.
Hydrogen
- B.
Nitrogen
- C.
Carbon
- D.
Oxygen
Correct Answer
B. NitrogenExplanation
Nitrogen is the element that normally forms three covalent bonds in organic compounds. This is because nitrogen has five valence electrons and needs three more to complete its octet. By forming three covalent bonds, nitrogen can achieve a stable electron configuration. Hydrogen can only form one covalent bond, carbon can form four covalent bonds, and oxygen can form two covalent bonds. Therefore, nitrogen is the only element among the options that can form three covalent bonds.Rate this question:
-
Hund's Rule Demystified: Electron Configuration Challenge
Hund's Rule Demystified: Electron Configuration Challenge
The Pauli Exclusion Principle Quiz: Test Your Quantum Knowledge
The Pauli Exclusion Principle Quiz: Test Your Quantum Knowledge
- Aeronautics Quizzes
- Aerospace Quizzes
- Agricultural Science Quizzes
- Astrology Quizzes
- Astronomy Quizzes
- Atom Quizzes
- Biochemistry Quizzes
- Biology Quizzes
- Biomechanics Quizzes
- Biostatistics Quizzes
- Biotechnology Quizzes
- Botany Quizzes
- Branches Of Science Quizzes
- Cytology Quizzes
- Easy Science Quizzes
- Ecology Quizzes
- Electrical Quizzes
- Embryology Quizzes
- Endocrinology Quizzes
- Engineering Quizzes
- Environmental Science Quizzes
- Epidemiology Quizzes
- Experiment Quizzes
- Forestry Quizzes
- Fossil Quizzes
- Gas Quizzes
- General Science Quizzes
- Genetics Quizzes
- Histology Quizzes
- Human Biology Quizzes
- Integrated Science Quizzes
- Invention Quizzes
- Library Science Quizzes
- Lighting Quizzes
- Liquid Quizzes
- Marine Biology Quizzes
- Microbiology Quizzes
- Molecular Biology Quizzes
- Nature Quizzes
- Neuroscience Quizzes
- Nuclear Science Quizzes
- Oceanography Quizzes
- Physics Quizzes
- Psychology Quizzes
- Science And Technology Quizzes
- Science Glossary Quizzes
- Science Knowledge Quizzes
- Science Practice Quizzes
- Scientific Method Quizzes
- Scientific Notation Quizzes
- Soil Science Quizzes
- Solar System Quizzes
- Solid Quizzes
- Zoology Quizzes
Back to top