9 questions
A sample of a hard, solid binary compound at room temperature did not conduct electricity as a pure solid but became highly conductive when dissolved in water. Which of the following types of interactions is most likely found between the particles in the substance?
Ionic bonds
Metallic bonds
Covalent bonds
Hydrogen bonds
At room temperature I2(s) is a molecular solid. Which of the following provides a characteristic of I2(s) with a correct explanation?
It has a high melting point because it has weak intermolecular forces.
It is hard because it forms a threedimensional covalent network.
It is not a good conductor of electricity because its valence electrons are localized in bonding and nonbonding pairs.
It is very soluble in water because its molecules are polar.
Which of the following could be the identity of a white crystalline solid that exhibits the following properties?
-It melts at 320°C.
-It does not conduct electricity as a solid.
-It conducts electricity in an aqueous solution.
C6H12O6(s)
NaOH(s)
SiO2(s)
Cu(s)
In solid methane, the forces between neighboring CH4 molecules are best characterized as
ionic bonds
covalent bonds
hydrogen bonds
ion-dipole forces
London (dispersion) forces
A certain crystalline substance that has a low melting point does not conduct electricity in solution or when melted. This substance is likely to be
a covalent network solid
a metallic solid
a polymer
an ionic solid
a molecular solid
A student is given a sample of a pure, white crystalline substance. Which of the following would be most useful in providing data to determine if the substance is an ionic compound?
Examining the crystals of the substance under a microscope
Determining the density of the substance
Testing the electrical conductivity of the crystals
Testing the electrical conductivity of an aqueous solution of the substance
Which of the following most likely describes the solid represented in the diagram above?
It is soft and is a poor thermal and electrical conductor.
It has a low melting point and is a poor thermal and electrical conductor as a solid.
It is a brittle, water-soluble electrolyte that is a poor thermal and electrical conductor as a solid.
It is malleable and is an excellent thermal and electrical conductor as a solid.
The structure of one form of boron nitride is represented above. This form of boron nitride is one of the hardest substances known. Which of the following best helps explain why boron nitride is so hard?
Boron ions and nitrogen ions are held together by ionic bonds.
Boron nitride is a network solid of atoms connected by covalent bonds with fixed bond angles.
Boron nitride is an alloy, and alloys are typically harder than the elements used to make them.
Boron nitride is a polymer made of long chains of boron atoms and nitrogen atoms held together by dispersion forces.
Three substances were studied in the laboratory, and the data in the table above were collected. Based on the data, which of the following shows the type of bonding in each substance?
Substance X: Network covalent; Substance Y: Ionic; Substance Z: Metallic
Substance X: Ionic; Substance Y: Molecular; Substance Z: Network covalent
Substance X: Molecular; Substance Y: Network covalent; Substance Z: Metallic
Substance X: Network covalent; Substance Y: Metallic; Substance Z: Ionic