Search found 21 matches
- Sat Dec 09, 2017 11:54 am
- Forum: Conjugate Acids & Bases
- Topic: Drawing resonance when comparing acid strength
- Replies: 1
- Views: 850
Drawing resonance when comparing acid strength
When drawing Lewis structures of HClO, HClO2, HClO3, HClO4 to compare acid strength due to electron withdrawing atoms, do we need to draw all of the resonance structures of HClO4 and HClO3?
- Wed Dec 06, 2017 10:33 pm
- Forum: Bronsted Acids & Bases
- Topic: 12.9(b)
- Replies: 1
- Views: 384
12.9(b)
Which of the following reactions can be classified as reactions between Brønsted acids and bases? For those that can be so classified, identify the acid and the base. NH4I(s) --> NH3(g) + HI(g) What makes NH4+ a Bronsted acid? Isn't it NH4I in solid form not aqueous on the left side of the reaction?
- Sun Dec 03, 2017 4:30 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Notes on 11.37
- Replies: 3
- Views: 609
Re: Notes on 11.37
It is a rule. When the coefficients in an chemical equation is multiplied by 2, the k is squared. This is a rule when manipulating equilibrium constants.
- Sun Dec 03, 2017 4:26 pm
- Forum: Coordinate Covalent Bonds
- Topic: Monodentate, Tridentate
- Replies: 1
- Views: 706
Re: Monodentate, Tridentate
You can draw the Lewis structure and see where lone pairs can possibly be contributed to the coordinate covalent bond. But for the most commonly used ligands, it would most convenient to memorize if they are mono, bi, tri, etc. -dentate.
- Fri Nov 24, 2017 12:19 am
- Forum: Hybridization
- Topic: Nitrogen hybridization
- Replies: 2
- Views: 422
Nitrogen hybridization
It was stated, "The promotion of electrons will occur if, overall, it leads to a lowering of energy by permitting the formation of more bonds." How come Nitrogen can be hybridized to sp3 if the number of possible bonds (3) doesn't' increase after hybridization?
- Thu Nov 23, 2017 1:02 pm
- Forum: Hybridization
- Topic: 4.73
- Replies: 2
- Views: 327
Re: 4.73
There are no unpaired electrons anywhere in CH2, and there is an even number of electrons total, so it cannot be a radical.
- Thu Nov 23, 2017 12:58 pm
- Forum: Hybridization
- Topic: Valence/valency?
- Replies: 1
- Views: 461
Valence/valency?
The book states, "It looks as though a carbon atom should have a valence of 2 and form two perpendicular bonds, but in fact it almost always has a valence of 4 (it is commonly “tetravalent”)..." Valence is not the number of valence electrons because Nitrogen's valency is 3. Could someone p...
- Sun Nov 19, 2017 8:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Octahedral vs Trigonal Bypyramidal family
- Replies: 3
- Views: 544
Re: Octahedral vs Trigonal Bypyramidal family
Every angle in an octahedral structure is 90 degrees. In other words, the orientation of the molecule doesn't matter, so the electron density you choose for the placement of the first lone pair doesn't matter.
- Sun Nov 19, 2017 7:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar ve non polar [ENDORSED]
- Replies: 7
- Views: 951
Re: Polar ve non polar [ENDORSED]
Yes, polar vs. non polar is geometrically unequal vs. equal distribution of negative charge in the atom.
- Wed Nov 08, 2017 3:20 pm
- Forum: Resonance Structures
- Topic: Formal Charge vs. Electronegativity
- Replies: 1
- Views: 663
Formal Charge vs. Electronegativity
For example, in SO2, the most stable structure is O=S=O which gives all three atoms formal charge of zero. However, O=S-O and O-S=O also exist, giving formal charge of -1 to the oxygen attached by single bond and formal charge of +1 to the central S atom. This would also make sense because O is more...
- Wed Nov 08, 2017 3:15 pm
- Forum: Resonance Structures
- Topic: 3.57 hydrogen sulfite
- Replies: 1
- Views: 340
Re: 3.57 hydrogen sulfite
Oxygen is more electronegative than sulfur and would attract the hydrogen more strongly than sulfur does.
- Sun Nov 05, 2017 9:48 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2760348
Re: Post All Chemistry Jokes Here
(Not exactly a joke but a cheeky pickup line)
Can I steal an electron so you can be my +1 to _____?
Can I steal an electron so you can be my +1 to _____?
- Sun Nov 05, 2017 12:52 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sulfur Dioxide?
- Replies: 3
- Views: 610
Sulfur Dioxide?
Why are there three resonance structures for SO2 when the one with two double bonds has the lowest formal charge? Why would the other two structures (one double, one single) be allowed to exist when they have higher formal charge?
- Wed Oct 25, 2017 5:10 pm
- Forum: Trends in The Periodic Table
- Topic: Effective Nuclear Charge Down a Group [ENDORSED]
- Replies: 1
- Views: 1255
Effective Nuclear Charge Down a Group [ENDORSED]
Does effective nuclear charge increase or decrease down a group? And as we move far down the table, what role do d orbitals play in shielding?
- Wed Oct 25, 2017 12:08 pm
- Forum: Trends in The Periodic Table
- Topic: Across a period vs. Down a group
- Replies: 3
- Views: 494
Re: Across a period vs. Down a group
I don't think we have to or are able to use trends to compare atoms of elements not in the same period or group.
- Sun Oct 22, 2017 1:16 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: P orbitals
- Replies: 4
- Views: 1834
Re: P orbitals
All three orbitals have the same energy, and the electron will fill any of them first. We designate that px is filled first, then py, and pz because of convention.
- Sun Oct 22, 2017 12:57 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 4s 3d or 3d 4s?
- Replies: 3
- Views: 1768
4s 3d or 3d 4s?
When filling up orbitals with electrons, we fill 4s before 3d. However, we write the electron configuration of V, for example, as [Ar] 3d3 4s2 because here, the 4s is now higher energy than the 3d. Does this mean that the energy levels of orbitals change relative to each other when they become fille...
- Sat Oct 14, 2017 4:15 pm
- Forum: Properties of Light
- Topic: Light as a wave or a particle [ENDORSED]
- Replies: 2
- Views: 282
Re: Light as a wave or a particle [ENDORSED]
Light acts as both a wave and a particle (wave-particle duality) but both natures have never been captured simultaneously in the same experiment. De Broglie's equation, λ=h/mv, illustrates this duality well because λ is wavelength (property of a wave) and m is mass (property of a particle.
- Sat Oct 14, 2017 4:10 pm
- Forum: Properties of Light
- Topic: Balmer and Lyman Clarification [ENDORSED]
- Replies: 3
- Views: 467
Re: Balmer and Lyman Clarification [ENDORSED]
Yes, these series apply only to Hydrogen because electron interaction for atoms with more than one electron will be much more complex. The electrons would interact with other electrons due to electrostatic forces, not accounted for here.
- Thu Oct 05, 2017 10:51 pm
- Forum: Balancing Chemical Reactions
- Topic: Order of Elements to Balance [ENDORSED]
- Replies: 5
- Views: 6958
Re: Order of Elements to Balance [ENDORSED]
Yes and if you have a molecule with a single compound, like O2 or N2, keep that for last because it's the easiest to manipulate.
- Thu Oct 05, 2017 10:48 pm
- Forum: Significant Figures
- Topic: Clarification
- Replies: 4
- Views: 568
Re: Clarification
The book and a previous post from a Moderator said to keep as many sig figs in your calculator as possible and round at the very end. But for problems like combustion, there is a step of addition and/or subtraction (of masses), so I don't know if we have to take off the significant digits based on t...