1. The general electron configuration for atoms of the halogen group is:
my answer: ns^2np^7
2. Consider the element with the electron configuration [Kr]5s^24d^7. This element is:
my answer: a transition metal
3. True/False: Cl- and S are isoelectronic:
my answer: true
4. Arrange the following ions in order of increasing ionic radius: Kk+, P3-, S2-, Cl-
my answer: K+, Cl-, S2-, P3-
5. For which of the following reactions is the enthalpy change equal to the second ionization energy of nitrogen?
my answer: N2+(G) — — >N3+(g) + e-
6. Which element will display an unusually large jump in ionization energy values between l3 and l4, its third and fourth ionization energies (Na, Mg, Al, Si, or P)?
my answer: Mg
7. For phosphorus atoms, which ionization energy will show an exceptionally large increase over the previous ionization energy (2nd, 3rd, 4th, 5th, or 6th)
my answer: 3rd
8. The successive ionization energies of a certain element are l1=589.5 kj/mol, l2=1145 kj/mol, l3=4900kj/mol, l4=6500kj/mol, and l5=8100 kj/mol. This pattern of ionization energies suggests that the unknown element is (K, Si, As, Ca, or S):
my answer: Si
9. Which of the following elements has the greatest electron affinity:
my answer: K
10. Which of the following is a basic oxide (CO2, MgO, As2O3, SO2, or Cl2O7):
my answer: MgO
11. Complete this statement: Coulomb’s law states that the magnitude of the force of interaction between 2 charged bodies is________________________
my answer: directly proportional to the product of the charges on
the bodies and inversely proportional to the square of
the distance separating them
12. The Lewis dot symbol for the calcium ion is:
my answer: :Ca:2+
13. Which one of the following ionic solids would have the largest lattice energy (NaCl, NaF, CaBr2, CsI, CaCl2):
my answer: CaBr2
14. Which of the following solids would have the highest melting point (NaF, NaCl, NaBr, NaI):
my answer: NaI
15. Which of the following solids would have the lowest melting point (KI, KBr, KCl, KF):
my answer: KCl
16. Which of these elements has the greatest electronegativity (Na, As, Ga, Cs, Sb):
my answer: As
17. A polar covalent bond would form in which one of the following pairs of atoms (Cl-Cl, Si-Si, Ca-Cl, Cr-Br, P-Cl)
my answer: Cl-Cl
18. What type of chemical bond holds the atoms together withing a water molecule:
my answer: polar covalent bond
19. Which of these bonds would have the greatest polarity (Si-P, Si-S, Si-Se, Si-Cl, Si-I):
my answer: Si-Cl
20. A nonpolar covalent bond would form in chich one of the following pairs of atoms (Na-Cl, H-Cl, Li-Br, Se-Br, Br-Br)
my answer: Na-Cl
21. The bond in which of the following pairs of atoms would be the least polar (C-Cl, C-C, C-H, O-C, N-C):
my answer: N-C
22. True/False: The electron dot formula for O2 shows:
my answer: a double bond
23. The total number of lone pairs in NCl3 is:
my answer: 10
24. The number of resonance structures for the sulfur dioxide molecule that satify the octet rule is:
my answer: 1
25. How many resonance structures are there for the cyclobutene molecule (C4H6; the four carbon atoms are arranged in a ring):
my answer: 2
26. What is the formal charge on the oxygen atom N2O (the atomic order is N-N-O):
my answer: -2
27. According to the VSEPR theory, the geometry of the SO3 molecule is:
my answer: trigonal planar
28. The geometry of the ClF3 molecule is best described as:
my answer: T-Shaped
29. According to the VSEPR theory, which one of the following would be linear (H2S, HCN, BF3, H2CO, SO2):
my answer: HCN
30. The bond angle in Cl2O is expected to be approximately:
my answer: 120
31. The F-S-F angles in SF6 are:
my answer: 109.5
32. According to the VSEPR theory, the ACTUAL F-AS-F bond angles in the AsF4- ion are predicted to be:
my answer: 109.5
33. Which one of the following molecules has a zero dipole moment:
my answer: CH2Cl2
34. What is the hybridization of the As atom in the AsF5 molecule:
my answer: sp3d2
35. Which of the following have the same geometries (NH2- and H20, NH2- and BeH2, H2O and BeH2, NH2-, H2O, and BeH2):
my answer: H2) and BeH2
36. The number of pi bonds in the oxalate ion (C2O42-) is:
my answer: 2
37. Consider the species Cl2+, Cl2, and Cl2-. Which of ehse species will be paramagnetic:
my answer: Only Cl2
38. Consider the species N2-, N2, and N2+. Which of these will be paramagnetic;
my answer: N2+ ad N2-
39. In which of the following would the bonding be weakened with the addition of an electron to form the negative molecular ion (B2, C2, N2, all of these, or none of these):
my answer: C2
40. Which of the following molecules is nonpolar (NH3, OF2, CH2Cl, H2O, or BeCl2):
my answer: NH3
psychfan29 wrote:
Just give it a shot! I just need someone to go through and tell me right/wrong. Pleeeeaaaase!!!!!
It’s been a while, so don’t count on me for perfectly correct answers.
P.S: Are you in AP Chem? These look fairly advanced.
psychfan29 wrote:
1. The general electron configuration for atoms of the halogen group is:
my answer: ns^2np^7
The outer shell should have 7, so I thought ns^2np^5. I thought all the n’s go in the same shell basically. I could be wrong though.
psychfan29 wrote:
2. Consider the element with the electron configuration [Kr]5s^24d^7. This element is:
my answer: a transition metal
Not sure. I remember there was a weird case where the d’s come before the p’s, and it goes 5s1 3p6 instead of 5s2 3p5 as you’d expect or something.
psychfan29 wrote:
3. True/False: Cl- and S are isoelectronic:
my answer: true
Don’t know what isoelectronic is.
psychfan29 wrote:
4. Arrange the following ions in order of increasing ionic radius: Kk+, P3-, S2-, Cl-
my answer: K+, Cl-, S2-, P3-
Do you get to use a periodic table? Just check which row they’re on (given their charges, they all have their outer shells filled) and order them by that (their e- configuration is equivalent to the noble gas in the row)
psychfan29 wrote:
5. For which of the following reactions is the enthalpy change equal to the second ionization energy of nitrogen?
my answer: N2+(G) — — >N3+(g) + e-
No idea.
psychfan29 wrote:
6. Which element will display an unusually large jump in ionization energy values between l3 and l4, its third and fourth ionization energies (Na, Mg, Al, Si, or P)?
my answer: Mg
No idea. Ionization energy = energy to kick out an electron, right? If between 3rd and 4th electron kicked out is highest energy, my guess is it had 8 (noble configuration) at that point, when it had 3+ (or 5-). I’d guess Al then since (if memory serves) it can be Al3+. [Note: I’ve never done this before - I’m just guessing from what I once knew]
psychfan29 wrote:
7. For phosphorus atoms, which ionization energy will show an exceptionally large increase over the previous ionization energy (2nd, 3rd, 4th, 5th, or 6th)
my answer: 3rd
No idea. IF my reasoning above is correct. P is 5+ right? Or is it 5-? If it’s 5+ I’d guess 6th, if it’s 5-, I’d guess 4th.
psychfan29 wrote:
8. The successive ionization energies of a certain element are l1=589.5 kj/mol, l2=1145 kj/mol, l3=4900kj/mol, l4=6500kj/mol, and l5=8100 kj/mol. This pattern of ionization energies suggests that the unknown element is (K, Si, As, Ca, or S):
my answer: Si
No idea.
psychfan29 wrote:
9. Which of the following elements has the greatest electron affinity:
my answer: K
If memory serves it’s bottom-left-most of periodic table (more protons+).
psychfan29 wrote:
10. Which of the following is a basic oxide (CO2, MgO, As2O3, SO2, or Cl2O7):
my answer: MgO
No idea.
psychfan29 wrote:
11. Complete this statement: Coulomb’s law states that the magnitude of the force of interaction between 2 charged bodies is________________________
my answer: directly proportional to the product of the charges on
the bodies and inversely proportional to the square of
the distance separating them
Isn’t this AP physics? Surprised you have it in a chem course... unless you’re taking this in europe where it’s mixed up. Anyway I think the answer’s right.
psychfan29 wrote:
12. The Lewis dot symbol for the calcium ion is:
my answer: :Ca:2+
I presume you meant to put two dots on top and on the bottom too.
psychfan29 wrote:
13. Which one of the following ionic solids would have the largest lattice energy (NaCl, NaF, CaBr2, CsI, CaCl2):
my answer: CaBr2
Depends on strength of ionic bonds. In simple cases like NaCl vs. NaBr vs. NaI I believe whichever one is lowest in column 7 (halogens).
I don’t remember what effect having multiples does (like CaCl2 vs. NaCl).
psychfan29 wrote:
14. Which of the following solids would have the highest melting point (NaF, NaCl, NaBr, NaI):
my answer: NaI
I think NaI too. I think it’s the lowest in column 7.
psychfan29 wrote:
15. Which of the following solids would have the lowest melting point (KI, KBr, KCl, KF):
my answer: KCl
I would have guessed KF. I thought it was highest in column 7.
psychfan29 wrote:
16. Which of these elements has the greatest electronegativity (Na, As, Ga, Cs, Sb):
my answer: As
If memory serves, whichever is closest to upper right corner (up to column 7 - I think F is most electronegative of all).
psychfan29 wrote:
17. A polar covalent bond would form in which one of the following pairs of atoms (Cl-Cl, Si-Si, Ca-Cl, Cr-Br, P-Cl)
my answer: Cl-Cl
Dunno. Never heard of polar covalent.
psychfan29 wrote:
18. What type of chemical bond holds the atoms together withing a water molecule:
my answer: polar covalent bond
We used to call them hydrogen bonds. Dunno if it’s the same.
psychfan29 wrote:
19. Which of these bonds would have the greatest polarity (Si-P, Si-S, Si-Se, Si-Cl, Si-I):
my answer: Si-Cl
I think that’s right, as Cl is most electronegative of the group.
psychfan29 wrote:
20. A nonpolar covalent bond would form in chich one of the following pairs of atoms (Na-Cl, H-Cl, Li-Br, Se-Br, Br-Br)
my answer: Na-Cl
I think NaCl is ionic. Br-Br should be covalent and (since they’re the same atom with same electronegativity) non-polar.
psychfan29 wrote:
21. The bond in which of the following pairs of atoms would be the least polar (C-Cl, C-C, C-H, O-C, N-C):
my answer: N-C
I’d guess C-C. N is slightly polar (on one side of the 4+/4- fence).
psychfan29 wrote:
22. True/False: The electron dot formula for O2 shows:
my answer: a double bond
by memory.
psychfan29 wrote:
23. The total number of lone pairs in NCl3 is:
my answer: 10
Don’t remember how to do electron dot structures.
psychfan29 wrote:
24. The number of resonance structures for the sulfur dioxide molecule that satify the octet rule is:
my answer: 1
I think it’s two. You have
O=S-O. and O.-S=O
I could be wrong though. My memory’s foggy.
psychfan29 wrote:
25. How many resonance structures are there for the cyclobutene molecule (C4H6; the four carbon atoms are arranged in a ring):
my answer: 2
I think that’s right. A square with the two doubles vertical first, then horizontal after that.
psychfan29 wrote:
26. What is the formal charge on the oxygen atom N2O (the atomic order is N-N-O):
my answer: -2
If I remembered how to do Lewis dot structures I’d remember this too...
psychfan29 wrote:
27. According to the VSEPR theory, the geometry of the SO3 molecule is:
my answer: trigonal planar
By memory. This is one of those interesting ones which are 1 and 1/3 bonds. I wish there was an actual way of drawing that.
psychfan29 wrote:
28. The geometry of the ClF3 molecule is best described as:
my answer: T-Shaped
I would have guessed bipyramidal (two free electron pairs on top and bottom - with triangle of F’s in middle), but then again my memory is failing me.
psychfan29 wrote:
29. According to the VSEPR theory, which one of the following would be linear (H2S, HCN, BF3, H2CO, SO2):
my answer: HCN
HCN is linear from memory. H-C=N
(hopefully the = with underline will come out as a triple bond)
psychfan29 wrote:
30. The bond angle in Cl2O is expected to be approximately:
my answer: 120
I don’t remember the angles. I think it’s tetrahedral though. Two Cl’s and two free e- pairs around the O.
psychfan29 wrote:
31. The F-S-F angles in SF6 are:
my answer: 109.5
I think this one is square bipyramidal (square of F’s around S, and one above and one below). I don’t remember the angle for those.
psychfan29 wrote:
32. According to the VSEPR theory, the ACTUAL F-AS-F bond angles in the AsF4- ion are predicted to be:
my answer: 109.5
I don’t remember where arsenic falls in the periodic table. You’d need it to count out the electrons and draw the correct shape. It’s either tetrahedral, trigonal bipyramidal, or square bipyramidal. (As in the middle)
psychfan29 wrote:
33. Which one of the following molecules has a zero dipole moment:
my answer: CH2Cl2
Depends!!! If it’s cis (Cl’s on same side of double bond), it has zero dipole. If it’s trans (Cl on opposite side of double bond), then it is polar.
psychfan29 wrote:
34. What is the hybridization of the As atom in the AsF5 molecule:
my answer: sp3d2
Not a clue. It’s one of those topics I don’t recall anything from. I don’t remember anything about how to compute hybrid orbitals.
psychfan29 wrote:
35. Which of the following have the same geometries (NH2- and H20, NH2- and BeH2, H2O and BeH2, NH2-, H2O, and BeH2):
my answer: H2) and BeH2
I don’t recall where beryllium falls in the table. You’d need to draw it out. I think NH2- is like NH3, except it has one electron pair in the place of one of the H’s (it’s therefore exactly like H2O in shape).
psychfan29 wrote:
36. The number of pi bonds in the oxalate ion (C2O42-) is:
my answer: 2
I’d have guessed one. Double bond = 1 sigma + 1 pi, triple bond = 1 sigma and 2 pis right? btw it should be two double bonded carbons with O-'s attached all around.
psychfan29 wrote:
37. Consider the species Cl2+, Cl2, and Cl2-. Which of ehse species will be paramagnetic:
my answer: Only Cl2
I don’t know what paramagnetic is.
psychfan29 wrote:
38. Consider the species N2-, N2, and N2+. Which of these will be paramagnetic;
my answer: N2+ ad N2-
idem.
psychfan29 wrote:
39. In which of the following would the bonding be weakened with the addition of an electron to form the negative molecular ion (B2, C2, N2, all of these, or none of these):
my answer: C2
Dunno how to do this.
psychfan29 wrote:
40. Which of the following molecules is nonpolar (NH3, OF2, CH2Cl, H2O, or BeCl2):
my answer: NH3
NH3 IS polar! (extra electron pair) I’d first guess OF2 or BeCl2 because of their symmetries. You have to figure out which one(s) has extra electron pairs after drawing their structures. Like I said I don’t remember where Be falls in the table.
I got my hands on a chem text. Appending a few corrections.
psychfan29 wrote:
2. Consider the element with the electron configuration [Kr]5s^24d^7. This element is:
my answer: a transition metal
Your answer is correct, but I didn’t know how to do it. I had a picture similar to this in the book
[IMG]http://genchem.chem.wisc.edu/sstutorial/Text5/Tx55/tx55p2.GIF[/IMG]
psychfan29 wrote:
3. True/False: Cl- and S are isoelectronic:
my answer: true
I looked up isoelectronic. Means same # of electrons (aka same electron configuration). Looking at the periodic table, the answer is false, because Cl- has the e- config of Argon (noble gas), and you have Sulfur atom (not ion!). If it was S2- then yeah, it’d be isoelectronic.
psychfan29 wrote:
4. Arrange the following ions in order of increasing ionic radius: Kk+, P3-, S2-, Cl-
my answer: K+, Cl-, S2-, P3-
Using the periodic table, I just realized they’re all isoelectronic with Argon. I would have guessed they’re the same size, but I guess that’s not the right answer. It’s either in decreasing or increasing order by atomic number then.
psychfan29 wrote:
6. Which element will display an unusually large jump in ionization energy values between l3 and l4, its third and fourth ionization energies (Na, Mg, Al, Si, or P)?
my answer: Mg
I’m going back and saying no idea on this one.
psychfan29 wrote:
7. For phosphorus atoms, which ionization energy will show an exceptionally large increase over the previous ionization energy (2nd, 3rd, 4th, 5th, or 6th)
my answer: 3rd
Same as above.
psychfan29 wrote:
9. Which of the following elements has the greatest electron affinity:
my answer: K
I was wrong on that one. It’s upper right corner. I’m not sure why though. I think it’s because it has a greater need to fill in the outer shell to get 8 (octet rule) - that seems to override the attraction from protons in the nucleus.
psychfan29 wrote:
13. Which one of the following ionic solids would have the largest lattice energy (NaCl, NaF, CaBr2, CsI, CaCl2):
my answer: CaBr2
I had it backwards. It’s NaF>NaCl>NaBr>NaI as you go down a column, using the same anion. Also LiF>NaF>KF>KRb>KCs as you go down a column, using the same cation. I suppose it has to do with F’s high electronegativity (upper right corner).
I still don’t know what multiples do.
psychfan29 wrote:
14. Which of the following solids would have the highest melting point (NaF, NaCl, NaBr, NaI):
my answer: NaI
Same... backwards. It’s NaF.
psychfan29 wrote:
15. Which of the following solids would have the lowest melting point (KI, KBr, KCl, KF):
my answer: KCl
KI. Reverse of above question.
psychfan29 wrote:
16. Which of these elements has the greatest electronegativity (Na, As, Ga, Cs, Sb):
my answer: As
My reasoning was correct. Your answer too.
psychfan29 wrote:
17. A polar covalent bond would form in which one of the following pairs of atoms (Cl-Cl, Si-Si, Ca-Cl, Cr-Br, P-Cl)
my answer: Cl-Cl
Cl-Cl is covalent, but it’s not polar (both atoms are the same). Cr-Br and Ca-Cl are ionic (since one’s a metal and the other halogen). P-Cl’s the only choice.
psychfan29 wrote:
18. What type of chemical bond holds the atoms together withing a water molecule:
my answer: polar covalent bond
I misread the question. I thought it said between water molecules. But yeah I think your answer is right.
psychfan29 wrote:
23. The total number of lone pairs in NCl3 is:
my answer: 10
Still don’t know.
psychfan29 wrote:
24. The number of resonance structures for the sulfur dioxide molecule that satify the octet rule is:
my answer: 1
I wrote it wrong. It should be without dots. I still think it’s two though.
O=S-O and O-S=O
psychfan29 wrote:
28. The geometry of the ClF3 molecule is best described as:
my answer: T-Shaped
I said bipyramidal, but I really meant triangular bipyramidal (as opposed to square bipyramidal)
psychfan29 wrote:
31. The F-S-F angles in SF6 are:
my answer: 109.5
“Square bipyramidal”! That means octahedron. At least that’s what the text says. My memory is so foggy I might have invented “square bipyramidal." Sorry!
psychfan29 wrote:
32. According to the VSEPR theory, the ACTUAL F-AS-F bond angles in the AsF4- ion are predicted to be:
my answer: 109.5
I’m gonna change my answer to no idea. Arsenic is in the same column as P and N (they’re crappy because 1. they have an odd number of electrons, 2. you can have PCl5 or PCl3) So I’m guessing you’d have a spare pair. Distorted tetrahedron (looks like trigonal bipyramidal, except one of the atoms would be an electron pair)?
psychfan29 wrote:
33. Which one of the following molecules has a zero dipole moment:
my answer: CH2Cl2
I wrote it backwards. polar if cis; nonpolar if trans.
psychfan29 wrote:
35. Which of the following have the same geometries (NH2- and H20, NH2- and BeH2, H2O and BeH2, NH2-, H2O, and BeH2):
my answer: H2) and BeH2
Looking at Beryllium it’s 2+, so I’m guessing BeH2 is linear (ionic). From my other answer, NH2- and H2O should be the same though.
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