chapter 10 key concepts

State the total number of valence electrons in CH2O.

12 valence electrons

Identify the number of bonding pairs and lone pairs of electrons in H2S.

2 bonding pairs and 2 lone pairs

State the number of valence electrons in a sulfur atom.

6

Arrange the following substances in order of decreasing magnitude of lattice energy. Cao, SrO, KCl, RbBr

Cao > SrO > KCl > RbBr

Place the following in order of decreasing bond length. H-F, H-I, H-Br, H-Cl

H-I > H-Br > H-Cl > H-F

Which of the two compounds, H2NNH2 and HNNH, has the strongest nitrogen-nitrogen bond, and which has the shorter nitrogen-nitrogen bond.

HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.

What are the general trends in electronegativity values?

Increase from left to right, decrease from top to bottom

Use Lewis theory to determine the chemical formula for the compound formed between Li and S.

Li2S

Which of the following ionic compounds would be expected to have the most exothermic lattice energy? LiF LiI LiCl LiBr

LiF

Which combination of elements will be most likely to form an ionic compound?

Metal and nonmetal

Which element can expand its valence shell to accommodate more than eight electrons? B N S Ar H

S

When is it appropriate to form double or triple bonds in a Lewis structure?

When the central atom does not have an octet of electrons

How many covalent bonds are usually formed by the element C?

four

The electronegativity is 2.1 for H and 4.0 for F. Based on these electronegativities, HF would be expected t

have polar covalent bonds with a partial positive charges on the H atoms.

Determine if the bond between each pairs of atoms would be pure covalent, polar covalent, or ionic. K and F

ionic

The bonding predicted by electronegativities in CsBr is __________.

ionic

The bonding predicted by electronegativities in Cl2 is __________.

nonpolar covalent

Determine if the bond between each pairs of atoms would be pure covalent, polar covalent, or ionic. C and N

polar covalent

Determine if the bond between each pairs of atoms would be pure covalent, polar covalent, or ionic. N and S

polar covalent

Using electronegativity values, the P-Cl bonds in PCl3 are __________.

polar covalent

Determine if the bond between each pairs of atoms would be pure covalent, polar covalent, or ionic. N and N

pure covalent