Search found 51 matches
- Wed Dec 04, 2019 11:20 pm
- Forum: Lewis Acids & Bases
- Topic: Strong Acids
- Replies: 6
- Views: 372
Re: Strong Acids
The ability to completely dissociate into solution and have two stable products in the solution.
- Wed Dec 04, 2019 11:19 pm
- Forum: Lewis Acids & Bases
- Topic: HF
- Replies: 4
- Views: 272
Re: HF
F- is not stable in solution and would react with the H+ ions in solution taking them out of solution.
- Wed Dec 04, 2019 11:18 pm
- Forum: Lewis Acids & Bases
- Topic: HCl and HI
- Replies: 10
- Views: 484
Re: HCl and HI
HI is stronger because the H-Cl bond is stronger than the H-I bond. A stronger acid needs to have weak bonds that are easily broken which allows H+ ions into solution.
- Wed Dec 04, 2019 11:16 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pOH Trends
- Replies: 3
- Views: 257
Re: pOH Trends
pOH is the opposite of pH. A high pOH indicates an acidic solution while a low pOH indicates a basic solution
- Wed Dec 04, 2019 11:12 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: How does anion stability contribute to relative acidity?
- Replies: 6
- Views: 427
Re: How does anion stability contribute to relative acidity?
A more stable anion means that the anion is able to be by itself without reforming the compound it was a part of. Acid strength refers to its ability to form products, namely H+. If the H+ reacts with the anion because the anion isn't stable then the acid is not as strong.
- Sun Dec 01, 2019 8:54 pm
- Forum: Hybridization
- Topic: Applying Hybridization
- Replies: 2
- Views: 218
Re: Applying Hybridization
Hybridization is used in covalent bonds as the atoms do not have enough unpaired electrons in their valence shells and need to hybridize in order to bond.
- Sun Dec 01, 2019 8:51 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Base
- Replies: 5
- Views: 336
Re: Conjugate Base
Conjugate bases of strong acids are very weak so they do not have affect the pH of the solution
- Sun Dec 01, 2019 8:49 pm
- Forum: Conjugate Acids & Bases
- Topic: Water as an Acid/Base
- Replies: 20
- Views: 1431
Re: Water as an Acid/Base
Water can be an acid or a base depending on what it is reacting with
- Sun Dec 01, 2019 8:47 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acids Vs. Bases
- Replies: 11
- Views: 839
Re: Acids Vs. Bases
Acids donate protons and bases receive protons, and acids dissociate and increase the H+ concentration whereas bases dissociate and the increase the OH- concentration
- Sun Dec 01, 2019 8:46 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Pka vs Ka
- Replies: 10
- Views: 525
Re: Pka vs Ka
pKa is a way to represent ka and is easier on the eyes as it uses the logarithmic scale.
- Mon Nov 18, 2019 3:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: CH2Cl2 structure
- Replies: 2
- Views: 169
Re: CH2Cl2 structure
That will depend on the question. If it asks you to draw the molecule as polar then put the Cl's on the same side so that the dipoles do not cancel. Otherwise, put them on opposite sides so that the dipoles do cancel.
- Mon Nov 18, 2019 3:35 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Notation
- Replies: 7
- Views: 370
Re: VSEPR Notation
You do not need to write the E0 in that situation.
- Mon Nov 18, 2019 3:35 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 2
- Views: 126
Re: Lone Pairs
Lone pairs push the bonded domains closer together and thus reduce the angle between those domains. The extent to which they are weakened differs from molecule to molecule.
- Mon Nov 18, 2019 3:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shapes
- Replies: 6
- Views: 371
Re: Shapes
We should know all of the geometries possible with up to 6 bonding domains and any combination of non bonding domains within those domains, i.e. 6 bonding domains of which one is a lone pair, etc..
- Mon Nov 18, 2019 3:32 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Pi Bond vs Sigma
- Replies: 6
- Views: 353
Re: Pi Bond vs Sigma
Sigma bonds are stronger than pi bonds because there is greater overlap between orbitals in sigma bonds.
- Thu Nov 14, 2019 11:35 am
- Forum: Ionic & Covalent Bonds
- Topic: Water molecules and ionic substances
- Replies: 5
- Views: 336
Re: Water molecules and ionic substances
They hydrogen bonding as well as the high polarity of water allows for the ionic substances to dissolve.
- Thu Nov 14, 2019 11:34 am
- Forum: Ionic & Covalent Bonds
- Topic: London Dispersion
- Replies: 13
- Views: 636
Re: London Dispersion
Every molecule has London dispersion forces which are created by momentary dipoles. Because they add up, larger molecules have stronger dispersion forces than smaller molecules.
- Thu Nov 14, 2019 11:33 am
- Forum: Ionic & Covalent Bonds
- Topic: covalent bonds
- Replies: 7
- Views: 435
Re: covalent bonds
3: polar covalent, nonpolar covalent, and coordinate covalent.
- Thu Nov 14, 2019 11:32 am
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 8
- Views: 481
Re: Bond Strength
Ionic bonds are stronger because there is a greater charge difference between atoms and thus a higher attraction.
- Thu Nov 14, 2019 11:31 am
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity
- Replies: 7
- Views: 431
Re: Electronegativity
You can use the periodic trends to find which atoms are more electronegative.
- Thu Nov 07, 2019 10:44 am
- Forum: Bond Lengths & Energies
- Topic: Bonding
- Replies: 7
- Views: 411
Re: Bonding
The third row of the periodic table and beyond can have expanded octets as they have the d orbital available and are also larger atoms.
- Thu Nov 07, 2019 10:44 am
- Forum: Bond Lengths & Energies
- Topic: Bond strengths
- Replies: 9
- Views: 501
Re: Bond strengths
I would say that in general, say that if a bond is shorter, it is stronger. I am not sure if there are any exceptions to this rule.
- Thu Nov 07, 2019 10:43 am
- Forum: Bond Lengths & Energies
- Topic: Short bond lengths vs long bond lengths
- Replies: 6
- Views: 425
Re: Short bond lengths vs long bond lengths
Shorter bonds mean that the nucleus has a better pull on the electrons involved in the bonding.
- Thu Nov 07, 2019 10:41 am
- Forum: Electronegativity
- Topic: Electron affinity
- Replies: 4
- Views: 263
Re: Electron affinity
Electron affinity is how much energy is released when an atom receives an electron.
- Thu Nov 07, 2019 10:40 am
- Forum: Electronegativity
- Topic: Trend of Electronegativity
- Replies: 22
- Views: 2022
Re: Trend of Electronegativity
Electronegativity increases up the periodic table and to the right.
- Mon Oct 28, 2019 10:53 pm
- Forum: Lewis Structures
- Topic: Lone Pairs
- Replies: 10
- Views: 404
Re: Lone Pairs
Lone pairs are electrons in the structure that are not shared between atoms or in other words, not involved in a bond. They are generally represented by dots around the atom that they belong to.
- Mon Oct 28, 2019 10:51 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ground State
- Replies: 11
- Views: 485
Re: Ground State
This is the state of the atom when it is at its lowest energy.
- Mon Oct 28, 2019 10:48 pm
- Forum: Resonance Structures
- Topic: Resonance Clarification
- Replies: 8
- Views: 360
Re: Resonance Clarification
This means that there are multiple possibilities for electron placement, but instead of there being different molecules with different electron placement, the electrons are delocalized and move freely giving the molecule more stability.
- Mon Oct 28, 2019 10:46 pm
- Forum: Octet Exceptions
- Topic: expanded octet?
- Replies: 9
- Views: 428
Re: expanded octet?
They do not have a filled d orbital and are thus able to have expanded octets.
- Mon Oct 28, 2019 10:45 pm
- Forum: Octet Exceptions
- Topic: aufbau principle
- Replies: 8
- Views: 328
Re: aufbau principle
The 3d is in the energy level of n=3 which has less energy than the 4s which is in the energy level of n=4.
- Thu Oct 24, 2019 12:25 am
- Forum: Ionic & Covalent Bonds
- Topic: Ionic Compounds
- Replies: 6
- Views: 224
Re: Ionic Compounds
Yes, one electron is given creating a cation while another atom receives an electron creating an anion. These are attracted to each other like magnets keeping the atoms bonded.
- Thu Oct 24, 2019 12:24 am
- Forum: Ionic & Covalent Bonds
- Topic: Resonance
- Replies: 12
- Views: 414
Re: Resonance
Their electrons are very mobile and delocalized which gives them stability.
- Thu Oct 24, 2019 12:21 am
- Forum: Ionic & Covalent Bonds
- Topic: Octet Rule
- Replies: 6
- Views: 195
Re: Octet Rule
They don't fill up their second shell, rather they lose electrons to fill only their first shell which only has two electrons.
- Thu Oct 24, 2019 12:20 am
- Forum: Ionic & Covalent Bonds
- Topic: Double Bond vs Single Bond Length
- Replies: 6
- Views: 519
Re: Double Bond vs Single Bond Length
In general, yes. The NO3 is a special case of resonance as its double bond is not on one of the bonds, but rather each bond is a bit stronger than a single bond and a bit weaker than a double bond.
- Thu Oct 24, 2019 12:18 am
- Forum: Lewis Structures
- Topic: Electronegativity
- Replies: 5
- Views: 221
Re: Electronegativity
You can look at the periodic table and using the trend that it increases up and to the right (excluding noble gases), be able to compare between two elements.
- Thu Oct 17, 2019 1:38 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electron spin
- Replies: 8
- Views: 252
Re: Electron spin
As long as you remember that +1/2 is a positive spin and -1/2 is a negative spin, that's all I think matters
- Thu Oct 17, 2019 1:35 am
- Forum: Photoelectric Effect
- Topic: Particle vs. Wave Model
- Replies: 5
- Views: 238
Re: Particle vs. Wave Model
Photons act as both waves and particles giving them properties of both. Because of this we describe them as being both
- Thu Oct 17, 2019 1:34 am
- Forum: Photoelectric Effect
- Topic: Photoelectric effect
- Replies: 5
- Views: 181
Re: Photoelectric effect
The different energy specifications for each metal will be given in the problem
- Thu Oct 17, 2019 1:31 am
- Forum: Properties of Electrons
- Topic: electron mass
- Replies: 8
- Views: 295
Re: electron mass
It will be given on the formula sheet.
- Thu Oct 17, 2019 1:31 am
- Forum: Properties of Electrons
- Topic: Momentum
- Replies: 11
- Views: 262
Re: Momentum
Momentum is the mass of a particle multiplied by its velocity. Momentum takes into account the mass of a particle in addition to its velocity.
- Thu Oct 17, 2019 1:29 am
- Forum: Properties of Light
- Topic: Constant for Speed of Light
- Replies: 14
- Views: 556
Re: Constant for Speed of Light
I would use the more specific value as it will give you a more exact answer.
- Thu Oct 10, 2019 11:00 am
- Forum: Balancing Chemical Reactions
- Topic: Combustion
- Replies: 17
- Views: 945
Re: Combustion
Combustion is when a carbon based compound reacts with oxygen to form carbon dioxide and water. To represent it in an equation you just have to react the initial compound with oxygen.
- Thu Oct 10, 2019 10:58 am
- Forum: Significant Figures
- Topic: Do we use molar mass ?
- Replies: 8
- Views: 230
Re: Do we use molar mass ?
Usually you don't want to use sig figs or round until the end of the problem, so until then use the whole value if you can.
- Thu Oct 10, 2019 10:57 am
- Forum: SI Units, Unit Conversions
- Topic: Accuracy vs Precision
- Replies: 11
- Views: 737
Re: Accuracy vs Precision
Accuracy is how close a value is to the accepted value while precision is how consistent you are with getting results, regardless if they are accurate or not. Hope this helps!
- Thu Oct 10, 2019 10:56 am
- Forum: Balancing Chemical Reactions
- Topic: Fractions
- Replies: 34
- Views: 1345
Re: Fractions
I would convert all fractions into an integer but using fractions is a good way to keep the numbers straight and helps initially with balancing.
- Thu Oct 10, 2019 10:55 am
- Forum: Molarity, Solutions, Dilutions
- Topic: G 25
- Replies: 7
- Views: 386
Re: G 25
You can double the solution 90 times by raising 2 to the 90 power and multiplying that with the initial volume.
- Wed Oct 02, 2019 6:59 pm
- Forum: Empirical & Molecular Formulas
- Topic: HW E17 part C
- Replies: 5
- Views: 237
Re: HW E17 part C
Yes, you would be correct. It looks like a trick question as for any compound or element, the number of atoms in a mole is constant.
- Wed Oct 02, 2019 6:58 pm
- Forum: Empirical & Molecular Formulas
- Topic: H25 Fundamental Question
- Replies: 3
- Views: 260
Re: H25 Fundamental Question
Those refer to the different oxidation states of those respective phosphorus atoms. In order to differentiate between the two oxides that would otherwise have the same name, they include the oxidation state in parentheses to specify which oxide they are referring to.
- Wed Oct 02, 2019 6:56 pm
- Forum: Empirical & Molecular Formulas
- Topic: Homework problem E1
- Replies: 9
- Views: 358
Re: Homework problem E1
The problem is asking how long the chain is where the chain is 1 mole of argon atoms long. It gives you the length of one of the argon atoms and you would then just multiply that by how many atoms are in a mole (Avogadro's number) to find how long the chain is.
- Wed Oct 02, 2019 6:54 pm
- Forum: Empirical & Molecular Formulas
- Topic: Rounding for Formulas
- Replies: 8
- Views: 407
Re: Rounding for Formulas
I don't know that there is a specific cutoff, but you should come fairly close to it. If you are off by a significant amount, I would go back and double check your work on that problem.
- Wed Oct 02, 2019 6:38 pm
- Forum: Empirical & Molecular Formulas
- Topic: Question about Theoretical Yield
- Replies: 8
- Views: 452
Re: Question about Theoretical Yield
No, they should be the same. If you calculate the theoretical yield in moles then you can convert that into grams as well. Grams and moles can be converted back and forth into one another so when calculating in one, you can just convert it to the other.