Ch 23 Covalent Bonding and Intermolecular Interactions
In carbon tetra-chloride, CCl4, what is true about the charge distribution?
The chlorine will be more negative than the carbon.
Ammonium nitrate (NH4NO3), a common fertilizer, is an ionically bonded substance involving two polyatomic ions, ammonium (NH4+) and nitrate (NO3-). Ammonium nitrate dissolves well in a polar solvent such as water. Which of the following statements best describes what happens when this fertilizer dissolves in water?
The compound breaks up into the two oppositely charged ions. The ions do not break apart.
Determine the metal and nonmetal nature of C and O. The compounds CO2 and CO exist. What prediction can you make about their properties?
Transparent gas
T/F: Covalent bonding occurs between nonmetal atoms.
True
T/F: Dispersion forces occur between nonpolar molecules.
True
When do polyatomic ions form crystals?
When they combine with metal atoms to form salts. and When they combine with other non-metal atoms.
When are molecules conductors of electricity?
When they combine with metals and are then melted or dissolved
Which of the following would best describe the characteristics of covalent materials? A brittle, transparent solid with a very high melting point, A shiny, malleable solid with a very high melting point, A non-conducting material with low melting and boiling points, likely liquid or gas at room temperature, A brittle, opaque solid with a very high melting point, A non-conducting solid at room temperature that will conduct if melted or dissolved.
A non-conducting material with low melting and boiling points, likely liquid or gas at room temperature
Which of the following pairs of elements woudl you expect to be covalently bonded (no ionic or metallic bond)? Co and Ni, P and O, K and F, Na and I
P and O
Bonds or molecules having an unequal distribution of charge with one end being positive, the other negative.
Polar
Having a pH value less than 7, meaning that the hydronium ion concentration is greater than in pure water.
acidic
a material in which other material dissolves
solvent
How would you describe the melting point of a substance formed by a substance containing molecular ions?
high
What type of bonding involves the sharing of electrons?
Covalent bonding
(T/F) Covalent molecules do not have well-defined shapes.
False
T/F: Metal and nonmetal substances combine to form molecules.
False
T/F: The triple covalent bond of carbon monoxide (CO) is a type of weak chemical interactions.
False
Chemical compounds between elements carbon and hydrogen. The compounds that make up gasoline are examples.
Hydrocarbons
Which of the following is a true statement about melting and boiling points in materials made of covalent molecules? Molecules that contain double bonds melt and boil at higher temperatures because the bonds are stronger, Molecules that contain triple bonds are the most likely to be gases at room temperature, Molecules that are polar have lower melting and boiling points than non-polar molecules, Hydrogen bonding between molecules increases melting and boiling points, Van der Waals (dispersion) forces lower melting and boiling points. 27
Hydrogen bonding between molecules increases melting and boiling points.
Ions composed of more than one covalently-bound atom.
Molecular ions
How would oxygen molecules behave if mixed with water?
They would dissolve poorly or not at all because they are not polar.
T/F: Molecular substances exhibit both covalent and intermolecular interactions.
True
Which of these substances consists of individual molecules? Diamond (C), Graphite(C), Water(H2O), Sodium Chloride(NaCl), Hydrogen(H2), Chlorine(Cl2) and ammonia(NH3)
Water, Hydrogen, Chlorine and ammonia
The chemical bond between two nonmetals characterized by sharing of valence electrons.
covalent bond
a separation of charge with one positive side and one negative side
dipole
a covalent bond involving two pairs of electrons shared between the two bound atoms
double bond
Forces between molecules
intermolecular forces
