chem ch 5 hw

Which set of properties would identify a unknown white solid as a molecular compound? I.Contains a metal. II.Has a definite crystal structure. III.Dissolves in water, but not in organic liquids. IV.Melts at 80 degrees Celsius. V.Does not conduct electricity when melted.

II, IV, V

Which physical property is most closely associated with covalent molecules?

It is a gas at room temperature.

The formula for phosphorus pentafluoride is ________.

PF5

The covalent bonding model is most useful in describing which of the following compounds?

SCl2

In the common nomenclature of ions, ous and ic are used as endings for the ions. In this system, which species is named with the ous ending?

The species with the lower positive charge.

The compound BrF3 would be called

bromine trifluoride.

Elements in Period 3 or below don't always "obey" the octet rule because they

can use s, p, and d orbitals for bonding.

A chemical bond formed between two identical atoms is a(an) ________ bond.

covalent

A chemical bond formed when two atoms share four electrons is a ________ bond; it is best described as ________.

double; covalent

A chemical bond formed when two atoms share two pairs of electrons is a ________ bond; it is best described as ________.

double; covalent

Which element listed is the least electronegative?

hydrogen

The bond angle in the molecule H2S is ________ because the ________

less than 109.5°; lone pairs force the hydrogen atoms closer together

The element least likely to obey the octet rule in forming chemical bonds is

neon

A molecule that contains three identical polar bonds to the central atom will be ________.

nonpolar if the geometry is planer triangular.

For the structure shown, the most likely elements are X = ________ and Y = ________.

oxygen; carbon

The carbon dioxide molecule is linear. The electronegativities of C and O are 2.5 and 3.5, respectively. Based on these values and on consideration of molecular geometry, the is ________ and the molecule is ________.

polar; non-polar

A molecule in which the central atom forms three single bonds and has one lone pair is said to have a ________ shape.

pyramidal

A chemical bond formed when two atoms share one pair of electrons is a ________ bond; it is best described as ________.

single; covalent

The element least likely to obey the octet rule in forming chemical bonds is

sulfur.

In a covalent compound the bond length can be defined as

the distance between two nuclei when repulsion and attraction are balanced.

A chemical bond formed when two atoms share six electrons is a ________ bond; it is best described as ________.

triple; covalent

In forming covalent bonds where the octet rule is obeyed, sulfur usually forms ________ bonds and chlorine usually forms ________ bonds.

two; one

Although noble gases do not normally form covalent compounds, XeO3 has been prepared. The systematic name of this compound is

xenon trioxide.