chem 121 quiz 3

exact questions

2

how many lone pairs are around the central atom in the correct lewis structure of XeF4

5

how many valence electrons does arsenic have

1/2

what is the bond order of He2+

B

which resonance form of OCN is the “best” structure and contributes most to the real molecule

1 and 2

which of the following are resonance structures for NO2-

10

how many total valence electrons are there in the NO+ ion

0, 3

in the lewis symbol for an aluminum atom, there are … paired and … unpaired electrons

2

how many electrons exist between 2 atoms in a single bond?

double bond

what type of bond is present in O2?

SF6, the bond dipoles are equal in magnitude and opposite in direction

which of the following molecules is non-polar and why?

• SF6

• CHCl3

• PCl3

4

how many pi bonds are in the caffeine molecule below?

P

which of the following atoms can violate the octet rule?

• C

• O

• P

• Ne

• N

trigonal pyramidal

the adrenaline molecule is shown below. what is the molecular geometry of the carbon atom circled below

sp

what is the hybridization of the carbon atom in the H2C2 molecule

Cl-, Ar, K+, Ca2+

which of the following is an isoelectronic series?

• H, He, B, Br

• Ne, Ar, Kr, Xe

• Mg2+, Ca2+, Sr2+, Be2+

• Cl-, Ar, K+, Ca2+

Cl

which of the following has the highest first ionization energy?

• Na

• Al

• Cl

• Mg

they decrease bond angles

how do lone pair electrons on the central atom typically affect bond angles in a molecule

90

what are the bond angles in CH4 molecule

octahedral

what is the electron domain geometry in the SF6 molecule

0

what is the formal charge in the oxygen atom of CO2

the electronegativity difference

which of the following factors determines whether a bond-dipole exists between two atoms?

the ability of an atom to attract electrons

which of the following best defines electronegativity?

trigonal pyramidal

the molecular geometry of NH3 is

Xe < Sb < Sn < Sr < Cs

correct order for atomic radius for Sr, Cs, Sb, Sn, and Xe?

N≡C

among the bonds N-C, N=C, and N≡C, which is the strongest?