Search found 48 matches
- Tue Jul 30, 2019 9:52 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: FeCl3 in water
- Replies: 1
- Views: 703
FeCl3 in water
Why doesn't the Cl- react with water in a reaction involving FeCl3 and water?
- Mon Jul 29, 2019 11:50 pm
- Forum: Lewis Acids & Bases
- Topic: Spectator Ions
- Replies: 1
- Views: 403
Spectator Ions
How can we tell which part of an acid/base molecule is a spectator ion and doesn't react?
- Mon Jul 29, 2019 11:05 am
- Forum: Coordinate Covalent Bonds
- Topic: Why can h20 only donate 1 lone pair?
- Replies: 5
- Views: 2225
Re: Why can h20 only donate 1 lone pair?
I think the shape of the molecule also plays a role since the way the electron pairs are positioned doesn’t really allow it to form 2 bonds.
- Wed Jul 24, 2019 11:54 pm
- Forum: Bronsted Acids & Bases
- Topic: Ammonia and phosphoric acid
- Replies: 1
- Views: 481
Ammonia and phosphoric acid
For the homework solution for Fundamentals J.9 (b), the equation written for the neutralization of ammonia and phosphoric acid doesn't include water. Do some neutralization reactions not produce water?
- Wed Jul 24, 2019 10:24 pm
- Forum: Naming
- Topic: Fe------ferrate? [ENDORSED]
- Replies: 8
- Views: 1321
Re: Fe------ferrate? [ENDORSED]
I think that's just the names that are used for naming these compounds. Cyano and cyanido are the same compound but cyano is just the older term. For iron, the Fe in the periodic table stands for ferrum, the Latin word for iron.
- Wed Jul 24, 2019 10:21 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: edta
- Replies: 8
- Views: 1920
Re: edta
It can bond with a metal at 6 different sites, creating the ring structure around the atom known as a chelate.
- Wed Jul 24, 2019 10:18 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: final exam
- Replies: 5
- Views: 1061
Re: final exam
We will probably have to memorize them for the final. I think we only get the constants/equation sheet and the periodic table for all tests.
- Tue Jul 23, 2019 10:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: Xenon -- why is it the only noble gas that can form bonds?
- Replies: 4
- Views: 4429
Re: Xenon -- why is it the only noble gas that can form bonds?
I think it's because the large radius of the atom negates part of the hold that the nucleus has on the valence electrons. When combined with a very electronegative atom, it can form bonds.
- Tue Jul 23, 2019 10:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Formula from Name
- Replies: 4
- Views: 567
Re: Formula from Name
Yes, we will most likely be tested on that during the final. It's also a part of the homework questions so it would be good to know how to do it.
- Mon Jul 22, 2019 10:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Why is AX3E2 linear?
- Replies: 8
- Views: 1417
Re: Why is AX3E2 linear?
AX3E2 is more a T-shaped molecule with the bound atoms in a side-ways T-shape. Imagine the trigonal bipyramidal structure of AX5 but remove two of the bound atoms of the trigonal part of the molecule.
- Mon Jul 22, 2019 10:01 pm
- Forum: Octet Exceptions
- Topic: Lewis Acids and Bases
- Replies: 10
- Views: 1314
Re: Lewis Acids and Bases
Lewis acids are the molecule that has the ability to accept an entire electron pair rather than sharing the electrons. The Lewis base is the donor of the electrons.
- Mon Jul 22, 2019 10:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Rotations and Shape
- Replies: 4
- Views: 679
Re: Rotations and Shape
I don't think it really matters since the molecule will still be the same with the same bonds.
- Sun Jul 21, 2019 3:24 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 394
Bond Angles
Would we have to know how to predict bond angles based on the shape of a molecule on a test?
- Sat Jul 20, 2019 8:32 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 7
- Views: 675
Re: Polarity
A bond that is polar has atoms with a difference in electronegativity, where one atom is slightly more positive and the other is slightly more negative. This causes an unequal distribution of e- as the more electronegative atom has a greater pull on the electrons.
- Thu Jul 18, 2019 8:48 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: charges and roman numerals
- Replies: 5
- Views: 924
Re: charges and roman numerals
The numerals indicate the charge of the atom in the molecule since transition metals can often have several ionic forms. For indium, the 3 indicates In 3+.
- Tue Jul 16, 2019 10:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: Inter and Intra
- Replies: 8
- Views: 2557
Re: Inter and Intra
Intermolecular forces are forces that are responsible for interactions between different individual molecules. Intramolecular forces are the forces that act within a molecule, binding together the atoms that make up a molecule.
- Tue Jul 16, 2019 8:26 pm
- Forum: Lewis Structures
- Topic: Molecule Formulas
- Replies: 5
- Views: 774
Molecule Formulas
Will we always be given the molecular formula on tests? In the homework, we're sometimes given only the names of the molecule such as periodate ion (2C.3).
- Tue Jul 16, 2019 7:38 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Difference between charge and formal charge [ENDORSED]
- Replies: 4
- Views: 911
Re: Difference between charge and formal charge [ENDORSED]
Formal charge depends on the bonds and lone pairs assigned to each atom in a structure. It compares the charge in the atom, calculated by the number of bonds divided by 2 and the number of electrons in the lone pairs, to the normal number of valence electrons.
- Mon Jul 15, 2019 10:57 pm
- Forum: Resonance Structures
- Topic: Test 2
- Replies: 1
- Views: 399
Test 2
Will we have to have questions on test 2 as complicated as 2B.13 where we have to draw out all the resonance structures for molecules like C14H10?
- Mon Jul 15, 2019 8:30 pm
- Forum: Dipole Moments
- Topic: Effect of size [ENDORSED]
- Replies: 7
- Views: 1375
Effect of size [ENDORSED]
Why does increasing the size or molar mass result in stronger attractive interactions?
- Mon Jul 15, 2019 8:25 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizing Power [ENDORSED]
- Replies: 8
- Views: 1228
Re: Polarizing Power [ENDORSED]
The polarizing power of a cation allows it to distort the electron field of the cation since the negative charge of the electrons is attracted to the positive charge on the cation.
- Fri Jul 12, 2019 9:54 pm
- Forum: Octet Exceptions
- Topic: breaking the octet
- Replies: 7
- Views: 1323
Re: breaking the octet
Those atoms have a d-orbital that can be filled after the s and p orbitals have been filled, allowing them to break the octet rule.
- Fri Jul 12, 2019 9:52 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 6
- Views: 839
Re: Formal Charge
It's the charge on each individual atom that can be calculated after drawing a Lewis structure. Each variation of the Lewis structure has different formal charges and the structure with the most neutral charge is often the best structure.
- Thu Jul 11, 2019 9:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: Homework 3.5
- Replies: 7
- Views: 1037
Re: Homework 3.5
The [Xe] fills in the 5s part. Xe's electron configuration is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6. The 4f14 5d10 6s2 come after the 5p6 to create the full electron configuration.
- Thu Jul 11, 2019 9:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic Character
- Replies: 4
- Views: 585
Re: Ionic Character
There are tables that list out the electronegativity values that you can use to compare to determine the difference in electronegativity. However, we won't get to use one on a test so it's mostly about understanding electronegativity trends in the periodic table. Electronegativity generally increase...
- Thu Jul 11, 2019 9:33 pm
- Forum: Resonance Structures
- Topic: Lewis Structures vs. Resonance
- Replies: 3
- Views: 595
Re: Lewis Structures vs. Resonance
Resonance is referring to the different ways that you could write out a Lewis structure since there are usually multiple valid ways you write one with differing types of bonds or lone pairs. While all the ways are valid, there are usually some structures that seem more stable.
- Wed Jul 10, 2019 9:40 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 6th edition 19b [ENDORSED]
- Replies: 2
- Views: 617
Re: 6th edition 19b [ENDORSED]
The 4+ means that 4 electrons have been removed. A natural Sn atom would have [Kr]4d^10 5s^2 5p^2. Taking away 4 electrons from the valence would make it [Kr] 4d^10.
- Wed Jul 10, 2019 12:03 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Number of orbitals given quantum numbers
- Replies: 3
- Views: 554
Re: Number of orbitals given quantum numbers
Orbital number is determined by the equation n^2. With n=2, you have both l=0 (s subshell) and l=1 (p subshell). For l=0, the s subshell only has 1 orbital (0). For l=1, the p subshell has 3 orbitals (+1,0,-1). Combined, there are 4 orbitals total.
- Sun Jul 07, 2019 4:21 pm
- Forum: Trends in The Periodic Table
- Topic: Element Names
- Replies: 8
- Views: 979
Element Names
For the periodic table that we use during tests, do we have to know the abbreviations for all the elements or will the names be written out for us?
- Sat Jul 06, 2019 8:40 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Chromium and Copper [ENDORSED]
- Replies: 1
- Views: 370
Chromium and Copper [ENDORSED]
What are the exceptions for chromium and copper that we need to know?
- Sat Jul 06, 2019 8:00 pm
- Forum: Properties of Electrons
- Topic: Electron Penetration
- Replies: 2
- Views: 651
Electron Penetration
What does it mean for an electron to penetrate the nucleus? In 1E.5 (b), it says that an electron in an s-orbital can penetrate the nucleus of an atom.
- Sat Jul 06, 2019 11:10 am
- Forum: Balancing Chemical Reactions
- Topic: Balancing Equations
- Replies: 6
- Views: 767
Re: Balancing Equations
I think it's easier to focus on one element at a time, usually starting with the element that only appears once on both sides. You equalize the amount on both sides with coefficients and then you see how that coefficient affects the other element amounts. Once you've figured that out, you just simpl...
- Fri Jul 05, 2019 10:31 am
- Forum: Student Social/Study Group
- Topic: Lecture July 5
- Replies: 2
- Views: 643
Re: Lecture July 5
I would appreciate a picture of today's notes as well. A picture of Wednesday's notes would be an extra bonus. My email is davidzhang211@yahoo.com. Thanks in advance!
- Thu Jul 04, 2019 3:57 pm
- Forum: Einstein Equation
- Topic: unit of energy
- Replies: 7
- Views: 976
Re: unit of energy
It's a unit of energy. In Joules, it's about 1.602x10-19 J.
- Thu Jul 04, 2019 12:20 pm
- Forum: Photoelectric Effect
- Topic: Threshold Energy
- Replies: 2
- Views: 400
Re: Threshold Energy
You would use the equation: total energy of photon= threshold energy + kinetic energy. You would need to find/be given the energy of the photon and the kinetic energy in order to determine the threshold energy.
- Thu Jul 04, 2019 10:16 am
- Forum: Photoelectric Effect
- Topic: Metals and Electrons
- Replies: 3
- Views: 567
Re: Metals and Electrons
I don't think there would be any change in the structural properties of the metal with a change in the electrical charge.
- Thu Jul 04, 2019 10:11 am
- Forum: Photoelectric Effect
- Topic: kinetic energy of electron
- Replies: 8
- Views: 1116
Re: kinetic energy of electron
There is only a certain amount of energy in a photon. If there is more energy than is needed to release the electron, then the extra energy is kinetic. If the energy to release the electron is the exact same as the photon, then there is 0 kinetic energy.
- Wed Jul 03, 2019 5:35 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Wednesday Lecture [ENDORSED]
- Replies: 1
- Views: 540
Wednesday Lecture [ENDORSED]
I missed the lecture for today (Wednesday). Could somebody give me a basic summary of what topics the professor went over?
- Wed Jul 03, 2019 12:50 pm
- Forum: Student Social/Study Group
- Topic: Test 1
- Replies: 1
- Views: 542
Test 1
How was Test 1 for you all? I wasn't able to make it that day to take the test. What was the average difficulty of the problems? Were they multiple choice, short answer, or both?
- Mon Jul 01, 2019 8:22 pm
- Forum: Limiting Reactant Calculations
- Topic: Are these important? [ENDORSED]
- Replies: 3
- Views: 684
Re: Are these important? [ENDORSED]
It's just a standard for the experiment environment since some reactions may change under certain pressures and temperatures.
- Fri Jun 28, 2019 10:03 pm
- Forum: Einstein Equation
- Topic: E=hv [ENDORSED]
- Replies: 52
- Views: 18036
Re: E=hv [ENDORSED]
The professor only mentioned metals when talking about the photoelectric effect. Can it happen to other materials as well?
- Thu Jun 27, 2019 7:15 pm
- Forum: Balancing Chemical Reactions
- Topic: Combustion Equation
- Replies: 21
- Views: 2710
Re: Combustion Equation
The equation should be balanced so that there are the same elements on both side of the equation. If there is nitrogen present in the fuel, it would also be present in one of the products of the combustion equation.
- Wed Jun 26, 2019 11:42 pm
- Forum: SI Units, Unit Conversions
- Topic: Use of Kelvin
- Replies: 6
- Views: 851
Re: Use of Kelvin
0 degrees Kelvin is the lowest theoretical possible temperature.
- Wed Jun 26, 2019 8:23 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Homework Problem G.13 in Fundamentals
- Replies: 3
- Views: 509
Re: Homework Problem G.13 in Fundamentals
You first have to find the concentration of the diluted solution. You can find the moles of the initial solution since they give you the molarity of the solution and an initial volume of 1 Liter. Since molarity is moles per volume, the initial solution has 0.20 moles.When the florist adds water, the...
- Wed Jun 26, 2019 7:55 pm
- Forum: Empirical & Molecular Formulas
- Topic: G.17 7th edition
- Replies: 1
- Views: 383
Re: G.17 7th edition
If you're looking at the solution manual for that problem, they use Liters as the unit of measurement. 250 mL is .250 Liters.
- Wed Jun 26, 2019 7:52 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Balancing Equations [ENDORSED]
- Replies: 25
- Views: 1961
Re: Balancing Equations [ENDORSED]
I would keep everything at whole numbers just to be safe. I haven't seen any chemical equations that have decimals or fractions as the stoichiometric coefficient.
- Tue Jun 25, 2019 8:38 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Dot in chemical formula
- Replies: 2
- Views: 5526
Dot in chemical formula
What does a dot in a chemical formula mean such as in problem E.23 when it asks about Na2CO3 (dot) 10H2O?
- Tue Jun 25, 2019 8:22 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G.5
- Replies: 3
- Views: 611
Re: G.5
You first have to convert the 2.111g of the solid sodium carbonate into mmol of Na+. I used dimensional analysis to do the conversion. Then you can take that answer to set up a proportion since you know that n/v = n/v. You know the values of mmol and volume for the initial solution and the mmol for ...