Orgchem 1

Multiple Choice

Why is understanding atomic structure important in organic chemistry?

• It helps explain chemical bonding and reactions.

• It is only relevant for inorganic chemistry.

• It is not necessary for understanding organic molecules.

• It only applies to physical chemistry.

Multiple Select

Which of the following statements about organic compounds is/are correct?

• Organic compounds are always derived from living sources.

• Organic compounds are based on carbon structures.

• Organic chemistry studies the structures and reactions of organic compounds.

• Organic compounds include metal salts and inorganic materials.

Multiple Choice

Which subatomic particles are found in the nucleus of an atom?

• Electrons and neutrons

• Protons and electrons

• Protons and neutrons

• Neutrons and photons

Fill in the Blank

The atomic number is equal to the number of ___ in an atom.

Multiple Select

Which of the following statements about atomic number and mass number are correct?

• Atomic number is the number of protons in the nucleus.

• Mass number is the sum of protons and neutrons.

• All atoms of a given element have the same mass number.

• Isotopes have different numbers of neutrons.

Multiple Choice

Which orbital is spherical in shape and has the nucleus at its center?

• s orbital

• p orbital

• d orbital

• f orbital

Multiple Choice

How many electrons can the third shell of an atom hold?

• 2

• 8

• 18

• 32

Fill in the Blank

Fill in the blank: The region of zero electron density that separates the lobes of a p orbital is called a ___.

Multiple Choice

Which of the following statements about p orbitals is correct?

• There are two perpendicular p orbitals in each shell.

• The lobes of a p orbital are separated by a region of maximum electron density.

• There are three perpendicular p orbitals of equal energy in each shell.

• p orbitals are always spherical in shape.

Multiple Select

Which of the following rules are used to determine the electron configuration of an atom?

• Aufbau principle

• Hund's rule

• Pauli exclusion principle

• All of the above

Multiple Choice

What did Van't Hoff and Le Bel propose about the spatial arrangement of carbon's four bonds?

• They are arranged in a straight line.

• They are arranged in a square planar geometry.

• They have specific spatial directions forming a tetrahedron.

• They are randomly oriented.

Multiple Choice

Which type of bond involves the sharing of electrons between atoms?

• Ionic bond

• Covalent bond

• Metallic bond

• Hydrogen bond

Multiple Choice

In the Lewis structure of carbon tetrachloride (CCl4), how many single bonds are present between carbon and chlorine atoms?

• 2

• 3

• 4

• 5

Fill in the Blank

Nitrogen has ___ valence electrons and forms three bonds in ammonia (NH3).

Multiple Select

Which of the following molecules have carbon forming four bonds?

• Methanol (CH3OH)

• Ammonia (NH3)

• Water (H2O)

• Methane (CH4)

Multiple Choice

Which element typically forms only one bond due to having a single valence electron?

• Oxygen

• Hydrogen

• Nitrogen

• Carbon

Multiple Choice

Which of the following bonds is always a sigma (σ) bond?

• Coordinate bond
• Single bond
• Triple bond
• Double bond

Multiple Choice

A π bond results from:

• random mixing of atomic orbitals
• head-on overlap of s orbitals
• sideways overlap of p orbitals
• parallel alignment of d orbitals

Multiple Choice

Which of the following statements is true about sigma (σ) and pi (π) bonds?

• Sigma bonds are weaker than pi bonds.
• Pi bonds allow free rotation; sigma bonds restrict rotation.
• Sigma bonds form between two atoms; pi bonds do not.
• Sigma bonds allow free rotation; pi bonds restrict rotation.

Multiple Choice

What is the hybridization of the central atom in methane (CH₄)?

• sp²
• sp
• sp⁴
• sp³

Multiple Choice

Which of the following molecules has a central atom with sp² hybridization?

• C2H4 (Ethylene)
• C2H6 (Ethane)
• C3H6 (Propylene)
• CH4 (Methane)

Multiple Choice

What is the hybridization of the carbon atom in ethene (C₂H₄)?

• d²sp³
• sp³
• sp²
• sp

Multiple Choice

What is the hybridization of the oxygen molecule in the picture?

• sp
• sp3
• sp2
• d2sp3