Unit 8 Test Review Flashcards
Molecular Compounds
What is the primary reason elements form chemical bonds?
To become more stable
Elements form bonds to achieve a more stable electron configuration.
How many electrons are shared in a single covalent bond?
2
A single covalent bond involves the sharing of two electrons.
In the water molecule (H₂O), how many electrons are being shared in total?
4
Each hydrogen atom shares one electron with oxygen, totaling four shared electrons.
Atoms form _______if they can attain a noble gas structure by sharing two or three pairs of electrons?
Double or Triple bonds
These bonds allow atoms to achieve a full outer electron shell.
What is the primary difference between a molecular compound and an ionic compound?
Molecular compounds form discrete molecules while ionic compounds form crystal lattices
This distinction is crucial in understanding the properties of different types of compounds.
Which compound would be an example of a covalent bond?
H₂S
H₂S consists of covalent bonds between hydrogen and sulfur.
Which type of bond forms between a metal and a nonmetal?
Ionic bond
Ionic bonds result from the transfer of electrons from metals to nonmetals.
When two nonmetals do not share electrons evenly, the resulting covalent bond will be?
polar
Polar covalent bonds occur due to differences in electronegativity.
_________ molecules occur naturally as pairs of two identical atoms covalently bonded together?
Diatomic
Examples include H₂, O₂, and N₂.
A compound that is weak, a poor conductor, and has low melting and boiling points is most likely?
Covalent
Covalent compounds generally have these characteristics.
What type of structure is characteristic of ionic compounds?
Lattice Structure
This structure contributes to the high melting and boiling points of ionic compounds.
How do molecular compounds typically dissolve?
In covalent solvents like hexane
Molecular compounds tend to dissolve in similar types of solvents.
Is hydrogen considered a metal or non-metal?
Non-metal
Hydrogen is classified as a non-metal despite its position in the periodic table.
A molecular formula provides information about the number of each type of _______in a molecule.
atom
It indicates the actual number of each type of atom present.
What represents the covalent bonds as dashes and shows the arrangement of covalently bonded atoms?
Structural Formula
This formula visually represents how atoms are connected in a molecule.
What is the representative unit of a molecular compound?
A Molecule
Unlike ionic compounds, which are represented by formula units, molecular compounds are represented by individual molecules.
CCl₄: Fill in the blanks - # S_________
S 4
CCl₄ has four single bonds between carbon and chlorine.
CCl₄: Fill in the blanks - # LP________
LP 0
There are no lone pairs on the central carbon atom.
CCl₄: Fill in the blanks - MG (Name)___________
Tetrahedral
The molecular geometry is tetrahedral due to the four bonds.
CCl₄: Fill in the blanks - Polar or Non-Polar_________
Non-Polar
The symmetrical arrangement of CCl₄ makes it non-polar.
BeF₂: Fill in the blanks - # S_________
S 2
BeF₂ has two single bonds between beryllium and fluorine.
BeF₂: Fill in the blanks - # LP________
LP 2
There are two lone pairs on the central beryllium atom.
BeF₂: Fill in the blanks - MG (Name)___________
Linear
The molecular geometry is linear due to the two bonding pairs and two lone pairs.
BeF₂: Fill in the blanks - Polar or Non-Polar_________
Polar
The presence of lone pairs and the difference in electronegativity make BeF₂ polar.
Complete the electronegativity difference for H-O
1.24
This difference indicates a polar covalent bond.
Complete the electronegativity difference for Na-Cl
2.23
This large difference indicates an ionic bond.
What is the energy required to break the bond between two covalently bonded atoms called?
Bond dissociation energy
The units for this energy are often given in kJ/mol.
What type of molecule is carbon dioxide (CO2)?
It contains two carbon–oxygen double bonds.
Is it possible to draw an electron dot structure for NO2 that satisfies the octet rule for all atoms?
No
What is a polyatomic ion?
A tightly bound group of atoms that behaves as a unit and has a positive or negative charge.
