Chemistry Chapter 9 Homework Assignment
Of the molecules PF3 and PCl3, which has bonds that are more polar?
PF3
What is the bond order of F−OF?
1
How many resonance structures can be drawn for ozone, O3?
2
What is the bond order of O2?
2
Show which electrons from the electron configuration are included in the Lewis structure.
2s22p3
Show which electrons from the electron configuration are included in the Lewis structure.
2s22p6
What is the bond order of CO?
3
The shortest nitrogen-nitrogen bond?
HNNH
What type of bonding occurs in sodium chloride, NaCL?
ionic
Determine whether the bond between each of the following pairs of atoms is purely covalent, polar covalent, or ionic.
purely covalent N and N polar covalent N and S C and O ionic Li and O
Consider the lattice energy of any ionic compound. What combination of ions and charges will produce the largest (in magnitude) lattice energies?
small ions and large charges
Does urea contain polar bonds?
yes
The formation of CsCl from Cs(s) and Cl2(g) involves the following steps: 1.Cs(s)→Cs(g) 2.1/2Cl2(g)→Cl(g) 3.Cs(g)→Cs+(g)+e− 4.Cl(g)+e−→Cl−(g) 5.Cs+(g)+Cl−(g)→CsCl(s) Which of these steps absorb energy and which release energy? Drag the items to the appropriate bin.
Absorbs energy 1 2 3 Releases energy 4 5
Which element has the highest (most negative) electron affinity?
Cl
Which statement best describes an O3 molecule?
Each atom in ozone is connected to another atom by a bond having a bond order of 1.5.
In the molecule FBr, which atom is the negative pole?
F
Order these compounds in order of increasing carbon-carbon bond strength.
H3CCH3<H2CCH2<HCCH
Order these compounds in order of decreasing carbon-carbon bond length.
H3CCH3>H2CCH2>HCCH
Which of the following two compounds has the strongest nitrogen-nitrogen bond? H2NNH2, HNNH
HNNH
If the following elements were involved in redox reactions, which noble-gas configuration would they most likely attain? Drag the appropriate elements to their respective bins.
He-Li Ne- Al, O Ar- K,P Kr- Y, Br
Rank the following series of molecules or ions in order of decreasing bond energy using their bond order to predict relative magnitude: oxygen difluoride: F−OF, oxygen: O2, carbon monoxide: CO Rank from highest to lowest bond energy. To rank items as equivalent, overlap them.
Highest bond energy carbon monoxide oxygen oxygen difluoride Lowest bond energy
Place the following elements in order of decreasing atomic radius: chlorine (Cl), lead (Pb), aluminum (Al), and fluorine (F). Rank the atomic radius from largest to smallest. To rank items as equivalent, overlap them.
Largest Pb Al Cl F Smallest
Rank the following compounds from largest to smallest according to their expected magnitude in lattice energy. Rank from largest to smallest magnitude in lattice energy To rank items as equivalent, overlap them.
Largest magnitude BeO MgS KBr KI CsI Smallest magnitude
Rank the following molecules or ions in order of decreasing bond length using their bond order to predict relative lengths: oxygen difluoride: F−OF, oxygen: O2, carbon monoxide: CO Rank from longest to shortest bond. To rank items as equivalent, overlap them.
Longest bond oxygen difluoride oxygen carbon monoxide Shortest bond
After doing some analysis, the probe determines that the gas pocket contains an element that has an ionization energy of I=1453kJ/mol and an electron affinity of EA=51.0kJ/mol. What is the identity of this element? Express your answer using an element symbol (e.g., Hg).
N
Which molecule would you expect to be a free radical?
NO2
Which of the following compounds has the highest boiling point?
NaI
A Venus probe detects an element with a first ionization energy of 2088 kJ/mol. Given the table of known ionization energies provided in the introduction, what is the most likely identity of this element?
Ne
Which choice represents a pair of resonance structures? Note that lone pairs have been omitted for clarity.
O=C=O and O≡C−O
Which of the following is true of an endothermic reaction?
Strong bonds break and weak bonds form.
Use formal charge to determine which of the following two Lewis structures is better (Figure 1) .
Structure I is the better Lewis structure.
An unknown element, X, reacts with rubidium to form the compound Rb2X. In other compounds this element also can accommodate up to 12 electrons rather than the usual octet. What element could X be?
Te
All three of the boron-fluorine single bonds in BF3 are polar. In which direction should the polarity arrows point?
away from the central boron atom
Carbon tetrafluoride (CF4 ) is used as a low-temperature refrigerant in refrigerators. What type of bonding occurs between the atoms of a CF4 molecule?
covalent
A probe sent to the planet Mercury has measured the electronegativities of several elements it has detected on the planet. Which element would you expect to identify as a metal?
element 2
The overall energy involved in the formation of CsCl from Cs(s) and Cl2(g) is −443 kJ/mol. Given the following information: heat of sublimation for Cs is +76 kJ/mol, bond dissociation energy for 12Cl2 is +121 kJ/mol, Ei1 for Cs is +376 kJ/mol, and Eea for Cl(g) is −349 kJ/mol. what is the magnitude of the lattice energy for CsCl? Express your answer numerically in kilojoules per mole.
magnitude of E = 667 kJ/mol
What type of bonding occurs in a sample of pure sodium, Na? In other words, how is one sodium atom held to another sodium atom?
metallic
