Bonding Flashcards
Valence electrons are xxx when forming a bond
Lost, gained, or shared
Bond
An attraction force
What type of attraction is needed to create a bond?
Proton - electron
Intramolecular bond
Bonds between atoms in a molecule
3 types of intramolecular bonds
1) Ionic
2) Covalent
3) Metallic
Ionic bond
The direct transfer of an electron from the metal to the nonmetal forms an ionic bond
Easiest way to identify an ionic bond?
Metal bonded to a nonmetal
Melting points of salts?
Extremely high
Ionic bonds create extremely…
Strong bonds
Electronegativity differences in ionic bonds?
Large END, greater than or equal to 1.7
The greater the END, the
More ionic character
Ionic don’t form a distinct molecule. What do they form?
Extended structures or crystals
Conductivity of ionic compounds
- Do NOT conduct in the solid phase
- Do conduct in the liquid state or when they’re dissolved in water
Why do ionic compounds conduct?
Due to free flowing ions when bonds break
Covalent bonds
Involve the sharing of electrons between nonmetals only
2 types of covalent bonds
1) Nonpolar covalent
2) Polar covalent
Nonpolar covalent bonds
Equal sharing of electrons between the same nonmetal element
END in nonpolar covalent bonds
= 0 since it’s the same element on either side of the bond
Examples of nonpolar covalent bonds
H2, F2, Cl2, Br2
What does the dot diagram of hydrogen look like?
H - H (does not complete the octet and can never form more than 1 bond)
Shape of ammonia
Pyramid
Shape of water molecule
90° angle
Shape of carbon dioxide
Linear
Polar bond
Unequal sharing of electrons between two different nonmetals
END in polar covalent bonds
Greater than 0 but less than or equal to 1.7
In an H - F bond, where are electrons shifting?
Electrons shift towards F because the EN of F is greater and electrons shift toward elements with high EN
Metallic bonds
A bond between two metals
Which of the following has metallic bonding?
CO2, NaCl, Hg, I2
Hg
Molecules with a symmetric distribution (S) of charge are
Nonpolar molecule (N)
Why do metals conduct electricity?
Due to a sea of mobile electrons
Molecules with an asymmetric distribution (A) of charge are
Polar molecule (P)
Shape of CH4
Tetrahedral
Common examples of tetrahedrals
CF4, CCl4, SiH4, GF4
Intermolecular bonds
Bonds between molecules
Hydrogen bonding
A bond between polar molecules where the hydrogen in one molecule is attracted to the very electronegative element with a small radius in the other molecule
Which of the following has the highest boiling point and why?
HCl, HF, HI, HBr
HF has the highest boiling point because it has the strongest hydrogen bonds (F has a high electronegativity and a small radius)
Molecule ion attraction
Dissolving ionic compounds or salts in water
NaCl(aq) conductivity
NaCl(aq) dissolves in water, dissociates into its free flowing ions, and conducts electricity
Hydrocarbons
Substances containing the elements hydrogen and carbon only
Why are hydrocarbons relatively nonpolar?
The END between carbon and hydrogen is small
Which phase of a substance has the weakest intermolecular forces?
Gas phase, least dense
Forces of attraction between nonpolar molecules (van der waal forces) increase as
The number of electrons increases
Highest boiling point =
Strongest intermolecular forces
Molecular substance
Anything that is covalent bonded
Examples of molecular substances
CO2, CCl4, C6H12O6
Compared to ionic bonds, covalently bonded substances have
Weaker bonds
Do molecular substances conduct electricity?
No, except for organic acids
Solubility
Does a substance dissolve or not dissolve
What is the rule for whether or not a substance would dissolve?
Like dissolves like
Is ethanol a polar or nonpolar molecule?
It behaves as a nonpolar molecule because it contains hydrocarbon chains
Is oil polar or nonpolar?
Nonpolar, doesn’t mix with water
