Search found 51 matches
- Tue Dec 03, 2019 10:46 am
- Forum: Amphoteric Compounds
- Topic: Amphoteric/acidic/basic
- Replies: 5
- Views: 450
Re: Amphoteric/acidic/basic
Usually you would use the periodic table for this. Metals form basic oxides while nonmetals form acidic oxides. metalloids tend to form amphoteric oxides
- Tue Dec 03, 2019 10:42 am
- Forum: Amphoteric Compounds
- Topic: water
- Replies: 4
- Views: 408
Re: water
In a basic solution water will form OH- while in an acidic solution water accepts an H+ and forms a hydronium ion H3O+
- Tue Dec 03, 2019 10:40 am
- Forum: Air Pollution & Acid Rain
- Topic: Reducing Acid Rain
- Replies: 4
- Views: 742
Re: Reducing Acid Rain
Decrease energy consumption, use renewable sources, burn clean coal
- Tue Dec 03, 2019 10:38 am
- Forum: Conjugate Acids & Bases
- Topic: Question on Problem 6.21
- Replies: 1
- Views: 282
Re: Question on Problem 6.21
This is because oxygen is more electronegative and less likely to share its electrons with a proton
- Tue Dec 03, 2019 10:33 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Strength of Strong Acids
- Replies: 2
- Views: 222
Re: Strength of Strong Acids
the strength of an acid can be ranked by the extent to which they ionize in an aqueous solution. Strong acids completely ionize, while weak acids only partially ionize
- Mon Nov 25, 2019 5:39 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Alkali Metals and Alkaline Earth Metals
- Replies: 2
- Views: 460
Re: Alkali Metals and Alkaline Earth Metals
They are also strong because they completely dissociate in water
- Mon Nov 25, 2019 5:37 pm
- Forum: Bronsted Acids & Bases
- Topic: J.9C and ionic equations
- Replies: 1
- Views: 229
Re: J.9C and ionic equations
For complete ionic equations, write the balanced equation but with all strong electrolytes written as dissociated ions.
- Mon Nov 25, 2019 5:36 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: chemical equation states
- Replies: 2
- Views: 246
Re: chemical equation states
Acids are all aqueous because they must be able to dissociate in water. You are correct that when water is added, both products are aqueous as well.
- Mon Nov 25, 2019 5:34 pm
- Forum: Biological Examples
- Topic: Coordination Compounds
- Replies: 2
- Views: 227
Re: Coordination Compounds
I believe there was a chart Dr. Lavelle had sent out
- Mon Nov 25, 2019 5:31 pm
- Forum: Naming
- Topic: roman numerals
- Replies: 7
- Views: 726
Re: roman numerals
I believe the II refers to the +2 charge of the nickel in the compound.
- Mon Nov 18, 2019 10:22 pm
- Forum: Dipole Moments
- Topic: Determining state based on intermolecular interactions
- Replies: 1
- Views: 239
Re: Determining state based on intermolecular interactions
There is no specific interaction that would guarantee liquid state at room temperature, but a general guideline would be that gases have the weakest intermolecular interactions at room temperature (London Dispersion), liquids have interactions with strengths somewhere in between, and solids have the...
- Mon Nov 18, 2019 10:19 pm
- Forum: Sigma & Pi Bonds
- Topic: HW 2F.3
- Replies: 2
- Views: 248
Re: HW 2F.3
I think that's because the textbook used the resonance structure where there is one single-bonded O and one double-bonded O, and so as a result there is only one pi bond.
- Mon Nov 18, 2019 10:15 pm
- Forum: Ionic & Covalent Bonds
- Topic: Study Group
- Replies: 8
- Views: 528
Re: Study Group
I'm interested in joining this group too! Where do you guys meet?
- Mon Nov 18, 2019 10:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: Is ionic or covalent stronger?
- Replies: 31
- Views: 17026
Re: Is ionic or covalent stronger?
ionic bonds are stronger because the molecules will form a tightly knit crystal lattice structure that is extremely strong.
- Mon Nov 18, 2019 10:13 pm
- Forum: Ionic & Covalent Bonds
- Topic: HS vs HO
- Replies: 4
- Views: 867
Re: HS vs HO
The intramolecular bond between HO would be stronger than the intramolecular bond between HS because of the stronger effective nuclear charge present in the nucleus of O. As a result, HO is more tightly bound.
- Wed Nov 13, 2019 11:37 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Covalent bonding
- Replies: 5
- Views: 396
Re: Covalent bonding
On the other hand, intramolecular forces such as covalent bonding occur between the individual atoms in a molecule.
- Wed Nov 13, 2019 11:34 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Intermolecular forces
- Replies: 10
- Views: 725
Re: Intermolecular forces
van der waals and london forces are terms that are typically used interchangeably.
- Wed Nov 13, 2019 11:32 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: intermolecular forces
- Replies: 8
- Views: 593
Re: intermolecular forces
An overall molecule has a dipole if there is a great difference in electronegativity between the individual atoms that compose that molecule.
- Wed Nov 13, 2019 11:31 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Intermolecular Forces
- Replies: 2
- Views: 172
Re: Intermolecular Forces
To determine the type of intermolecular force present, you look at the the difference in electronegativity between the atoms in a molecule. If the there is a great difference in electronegativity, a dipole-dipole interaction will occur with other polarized molecules or a dipole-induced dipole intera...
- Wed Nov 13, 2019 11:28 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Single/Double Bonds in Resonance
- Replies: 6
- Views: 403
Re: Single/Double Bonds in Resonance
Single, double ,and triple bonds are all considered one region of electron density in the VSEPR model. So regardless of resonance structures, the shape of the VSEPR model won't be affected.
- Wed Nov 06, 2019 11:03 pm
- Forum: Dipole Moments
- Topic: Dipole moments
- Replies: 5
- Views: 433
Re: Dipole moments
^^ Building upon what they said, dipole moments occur because electrons are pulled towards the more electronegative side of the bond, so one side becomes more negatively charged while the other side becomes more positively charged
- Wed Nov 06, 2019 10:59 pm
- Forum: Bond Lengths & Energies
- Topic: Midterm
- Replies: 9
- Views: 554
Re: Midterm
^^ Yep, he said he would try his best to get it done in a week.
- Wed Nov 06, 2019 10:58 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: smaller cations
- Replies: 3
- Views: 286
Re: smaller cations
Cation radii follows the normal atomic radii trend. It increases across a period and decreases down a group. This is because moving across, the number of protons increases, thus increasing effective nuclear charge and decreases the size. If we have 3 cations that are isoelectronic, for instance: Na+...
- Wed Nov 06, 2019 10:53 pm
- Forum: Resonance Structures
- Topic: Formal Charge Question
- Replies: 16
- Views: 946
Re: Formal Charge Question
The most stable and ideal resonance structure would have a formal charge of 0 on each individual atom. However, that may not happen if the molecule is charged. If we have something such as SO4(2-), then the individual formal charges on each individual atom should add up to a total of -2. If a resona...
- Wed Nov 06, 2019 10:48 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Central atom: formal charge v electronegativity
- Replies: 3
- Views: 246
Re: Central atom: formal charge v electronegativity
The least electronegative atom goes in the center since it is less likely to interact with the electrons in surrounding molecules. The more electronegative atoms typically go on the outside. It is ideal if all the formal charges are 0, but if that is not possible then negative formal charges should ...
- Tue Oct 29, 2019 12:17 pm
- Forum: Dipole Moments
- Topic: Atom Shapes
- Replies: 2
- Views: 119
Re: Atom Shapes
Yep! It's going to be covered in the next unit and will be included in the final, but will not be part of our midterm.
- Tue Oct 29, 2019 12:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: When is the midterm?
- Replies: 5
- Views: 294
Re: When is the midterm?
The locations should be reposted again by the next class session, if not he will most likely email them to us.
- Tue Oct 29, 2019 12:13 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm
- Replies: 10
- Views: 559
Re: Midterm
I don't believe locations for the midterm have been released yet.
- Tue Oct 29, 2019 12:08 pm
- Forum: Bond Lengths & Energies
- Topic: bond lengths
- Replies: 10
- Views: 602
Re: bond lengths
Double and Triple bonds have more electrons, so they exert a stronger attractive force on the nuclei of the other atom, thus pulling the two atoms close together and reducing the bond length.
- Tue Oct 29, 2019 12:05 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar vs Nonpolar bond strength
- Replies: 2
- Views: 729
Re: Polar vs Nonpolar bond strength
Polarity definitely affects the bond strength. When you are talking about intermolecular bonds, polar bonds will always be stronger than non-polar bonds because polar bonds have dipole-dipole attraction, which are much stronger than the London Dispersion Forces that are only present in non-polar bon...
- Tue Oct 22, 2019 10:35 pm
- Forum: Trends in The Periodic Table
- Topic: Periodic Trend Exceptions
- Replies: 7
- Views: 293
Re: Periodic Trend Exceptions
Another exception is electron affinity for noble gases. Electron affinity increases across a period until you get to a noble gas, because when an electron is added to the full shell of a noble gas, the stability of the atom becomes destroyed.
- Tue Oct 22, 2019 10:32 pm
- Forum: Trends in The Periodic Table
- Topic: Ionic Radius
- Replies: 4
- Views: 221
Re: Ionic Radius
This is also because anions have more electrons, so there is more electron-electron repulsion present that causes the radius to be bigger.
- Tue Oct 22, 2019 4:29 pm
- Forum: *Particle in a Box
- Topic: Midterm
- Replies: 17
- Views: 4290
Re: Midterm
You can go into the SAC's test bank and see if they have Lavelle's old midterm
- Tue Oct 22, 2019 4:24 pm
- Forum: DeBroglie Equation
- Topic: Velocity
- Replies: 13
- Views: 962
Re: Velocity
For tests I believe everything will be in SI units. If not, we will get the conversion factors
- Tue Oct 22, 2019 4:16 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy for the 2nd Electron
- Replies: 3
- Views: 133
Re: Ionization Energy for the 2nd Electron
Conceptually, the 2nd ionization energy is higher than the first because there is less electron-electron repulsion present in the atom, which results in the remaining electrons being "held" onto tighter. Similarly, the 3rd ionization energy will always be higher than the 2nd, and so on.
- Tue Oct 22, 2019 4:11 pm
- Forum: Trends in The Periodic Table
- Topic: Hw Help 1F.22
- Replies: 2
- Views: 284
Re: Hw Help 1F.22
I believe there are color-coded periodic tables available that tell you what each type of element is:
ex. https://www.chemicalsafetyfacts.org/wp- ... d-650w.jpg
ex. https://www.chemicalsafetyfacts.org/wp- ... d-650w.jpg
- Wed Oct 16, 2019 4:18 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Energy levels
- Replies: 3
- Views: 253
Re: Energy levels
The 4d orbital does have a higher energy level than the 5s orbital. Higher principal quantum numbers aren't necessarily always associated with higher energy levels, such as this case of 4d vs. 5s.
- Wed Oct 16, 2019 4:09 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Atomic Radius
- Replies: 18
- Views: 681
Re: Atomic Radius
The atomic radius is half the distance between the nuclei of two identical atoms bonded together. For the purpose of this class I don't think we would be calculating the exact value of the radius.
- Wed Oct 16, 2019 4:06 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electron spin
- Replies: 8
- Views: 304
Re: Electron spin
I believe +1/2 and -1/2 are the only possible spin states
- Wed Oct 16, 2019 3:47 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Difference Between Ground and Excited States
- Replies: 3
- Views: 161
Difference Between Ground and Excited States
Can someone summarize how to tell whether an atom is in the ground state or excited state?
- Tue Oct 15, 2019 2:14 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Time of Use
- Replies: 5
- Views: 119
Re: Time of Use
The question will most likely ask you to calculate the uncertainty of momentum or the uncertainty in position
- Thu Oct 10, 2019 7:15 pm
- Forum: SI Units, Unit Conversions
- Topic: Problem E27
- Replies: 1
- Views: 258
Re: Problem E27
a) you know that the molar mass of water is ~18g, and that one mole of water contains 6.022 x 10^23 water molecules. To find the mass per molecule, simply divide the total molar mass by the number of water molecules b) molar mass of water is 18g, to find number of moles in 1kg divide 1kg (1000g) by ...
- Thu Oct 10, 2019 5:27 pm
- Forum: Properties of Light
- Topic: Energy Levels
- Replies: 8
- Views: 482
Energy Levels
Can someone pls explain why n=1 is the ultraviolet region, but when an electron drops down from a higher level, it loses energy? I was under the assumption that waves in the ultraviolet region have higher energy.
- Thu Oct 10, 2019 5:15 pm
- Forum: Empirical & Molecular Formulas
- Topic: Homework F9
- Replies: 4
- Views: 177
Re: Homework F9
^^ The technique above is what I was taught -- basically think of all of the decimals as fractions where you have to get rid of the denominator
- Thu Oct 10, 2019 5:11 pm
- Forum: Limiting Reactant Calculations
- Topic: L 35 Textbook Typo [ENDORSED]
- Replies: 4
- Views: 408
Re: L 35 Textbook Typo [ENDORSED]
@ ATingin_3I the t would stand for ton, and 1 ton equates to 1000kg
- Tue Oct 08, 2019 2:06 pm
- Forum: Limiting Reactant Calculations
- Topic: Test 1
- Replies: 11
- Views: 532
Re: Test 1
I think it will be sufficient if you do all the recommended problems since that gives you a good overview of all the different types of problem situations.
- Wed Oct 02, 2019 6:26 pm
- Forum: Limiting Reactant Calculations
- Topic: Limiting reactant
- Replies: 4
- Views: 253
Re: Limiting reactant
The limiting reactant should be the one that produces the fewest number of moles of product. That can be figured out by comparing mole ratios between that reactant and the product.
- Wed Oct 02, 2019 2:32 pm
- Forum: Limiting Reactant Calculations
- Topic: HW M19
- Replies: 2
- Views: 102
Re: HW M19
For all combustion problems, you would use molar ratios to solve for the empirical formula. For instance, in this problem you are given that there is 0.682 g of CO2 produced. The molecular weight of CO2 is around 44g, so you divide 0.682/44 to calculate the number of moles of CO2 that is produced in...
- Wed Oct 02, 2019 2:21 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Molar mass vs. Molecular Weight
- Replies: 5
- Views: 1303
Re: Molar mass vs. Molecular Weight
^^ That is correct! We can use water as an example. For instance, water is made of hydrogen and oxygen. Hydrogen has a molar mass of 1.0079g while oxygen has a molar mass of 15.999. The values of molar mass are found from the periodic table. Meanwhile, water is a molecule made up of oxygen and hydro...
- Wed Oct 02, 2019 8:37 am
- Forum: Student Social/Study Group
- Topic: Study Group Fall 2019
- Replies: 32
- Views: 2873
Re: Study Group Fall 2019
I'm also interested! Hopefully we can get a few more people
- Tue Oct 01, 2019 11:34 am
- Forum: Significant Figures
- Topic: Determining how many sig figs to use
- Replies: 3
- Views: 130
Re: Determining how many sig figs to use
Typically your answer would contain the least amount of sig figs that is present in the question. Since in the example the number 2.1 has the least amount of sig figs of 2, your solution would contain 2 sig figs. As a result I believe your decimal answer would be rounded to 5.0. Hopefully someone el...