Search found 61 matches
- Sun Jan 17, 2021 2:46 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Chart with Gas Pressures
- Replies: 8
- Views: 22
Re: ICE Chart with Gas Pressures
Yup exactly you want to use bar and you want to use pressures not molarity. Pressure equilibrium is different from concentration of molarity.
- Sun Jan 17, 2021 2:45 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Amphiprotic
- Replies: 8
- Views: 23
Re: Amphiprotic
Amphiprotic is anything that can act as a Base or an acid by giving always or accepting electrons. Water does this in all reactions as when it’s bonded with an strong acid it creates acid or with a strong base it creates a base.
- Sun Jan 17, 2021 2:37 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka x Kb
- Replies: 11
- Views: 33
Re: Ka x Kb
Ka and Kb will always = 1x 10^-14 which is the kW value. The reason why is because these two values are the concentrations of hydroniums and OH, which shows the basicity or acidity of the solution. When you do the log base of these values it gives you the pH. So it has to add up to 14.
- Sun Jan 17, 2021 2:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Number 4
- Replies: 4
- Views: 26
Re: Sapling Number 4
Make sure all values are correct under the square root. Some may be negative but when multiplied with the C which should be a negative value you’ll get a positive X.
- Sun Jan 17, 2021 2:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice Box Method
- Replies: 14
- Views: 39
Re: Ice Box Method
For the ice box method you have to look at the reactants and products. In most reactions you will see the reactants producing the products so the reactants will decrease. However in some cases if you’re working backwards you’ll have to subtract.
- Sun Jan 10, 2021 8:38 pm
- Forum: Ideal Gases
- Topic: Units of Temperature
- Replies: 82
- Views: 287
Re: Units of Temperature
For the ideal gas law you want to use Kelvins because it often cancels with the R.
- Sun Jan 10, 2021 8:37 pm
- Forum: Ideal Gases
- Topic: Ideal Gas Equation units
- Replies: 4
- Views: 14
Re: Ideal Gas Equation units
P standing for pressure should be in atm, V is the volume which should be in Liters. n is the moles of what you have, r is the constant that should be in ATM or just the same as whatever your P was. Finally T meaning temperature should be in Kelvins.
- Sun Jan 10, 2021 8:36 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 913
Re: Kc vs Kp
Use KP when you have anything to do with pressure. If you see any given partial pressure you want to use KP while KC is for varying molarity/ amount of the product/reactants you have.
- Sun Jan 10, 2021 8:34 pm
- Forum: Ideal Gases
- Topic: Units for Pressure
- Replies: 41
- Views: 815
Re: Units for Pressure
Professor Lavelle said to use the atm for pressure. He said that it’s not too different and he prefers atm since it’s been around longer.
- Sun Jan 10, 2021 8:34 pm
- Forum: Ideal Gases
- Topic: value of R
- Replies: 24
- Views: 74
Re: value of R
R is just the constant so you only use different R values dependent on the values that are in front of you. So if you have atm as one of the pressures you will use the R value with atm.
- Wed Dec 16, 2020 6:03 pm
- Forum: Lewis Acids & Bases
- Topic: Water
- Replies: 62
- Views: 490
Re: Water
Water is amphoteric, it has the ability to act as an acid or base. Water acts as a base when mixed with acid and vice versa, this is a very important topic in acids in bases because often most acids/bases are mixed with water to truly understand their acidity or basicity.
- Wed Dec 16, 2020 6:01 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 20
- Views: 87
Re: Lewis vs Bronsted
The important difference between lewis and Bronsted is the definition. Lewis acid/base definition is based on the accepting or donating of pairs of electrons while Bronsted is based on the accepting and donating of a proton in the form of an H+ ion.
- Wed Dec 16, 2020 6:00 pm
- Forum: Lewis Acids & Bases
- Topic: Ligands
- Replies: 6
- Views: 58
Re: Ligands
A ligand is anything that bonds to a coordinate covalent compound. Ligands always have a spare electron pair which allows them to bind and form a compound. Some ligands can be bidentate or tridentate meaning they have 2 electron pair donors or three.
- Wed Dec 16, 2020 5:59 pm
- Forum: Lewis Acids & Bases
- Topic: Acids & Bases
- Replies: 9
- Views: 77
Re: Acids & Bases
Theres many different types of ways to define an acid and a base. A Lewis base and acid, the base being the one that donates electrons while the acid is the one accepting. By the Bronsted definition, the acids are the ones releasing an H+ and bases accepting an H+.
- Wed Dec 16, 2020 5:57 pm
- Forum: Polyprotic Acids & Bases
- Topic: Which one is more acidic: H3PO3 or H3PO4
- Replies: 9
- Views: 69
Re: Which one is more acidic: H3PO3 or H3PO4
Anytime you have hydrogens and oxygens and you are determining strength of acid, always look at the number of oxygen. When you have more oxygen it stabilizes the structure much better with more oxygen than less after losing a hydrogen.
- Sun Dec 06, 2020 8:18 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric - how to tell if it is an acid or base
- Replies: 4
- Views: 62
Re: Amphoteric - how to tell if it is an acid or base
When you are trying to determine amphoteric compound in a reaction always look for where the hydrogen goes. If it leaves one compound then that one is the acid and the other is the base. Look at the reactants and the products to figure that out.
- Sun Dec 06, 2020 8:16 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric
- Replies: 11
- Views: 207
Re: Amphoteric
Amphoteric compounds are compounds that can act as either bases or acids depending on what elements are around them. Amphiprotic compounds can accept and donate hydrogens.
- Sun Dec 06, 2020 8:09 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Why is HF not classified as a strong acid?
- Replies: 19
- Views: 117
Re: Why is HF not classified as a strong acid?
HF cannot be classified as a strong acid because fluorine has the highest electronegativity on the periodic table of element so it holds onto that hydrogen very tightly making it not a strong acid, but do not forget it is still an acid.
- Sun Dec 06, 2020 8:07 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Negative pH of acid
- Replies: 16
- Views: 68
Re: Negative pH of acid
There is no negative PH. It can only range to the scale of 0-14.
- Sun Dec 06, 2020 8:05 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strengths of Acids: Polarity
- Replies: 6
- Views: 62
Re: Strengths of Acids: Polarity
When looking at the strength of acids always look at its ability to give off a hydrogen. When its a bigger a element it has longer bonds so it has a smaller bond on the hydrogens. But I see your point and yes stronger acids typically have a higher polarizability because it has more electrons and a l...
- Sun Nov 29, 2020 8:47 pm
- Forum: Hybridization
- Topic: Sapling #11
- Replies: 19
- Views: 115
Re: Sapling #11
Most important part is to first read the question and understand what they are asking. They say to look at a phosphorous atom so it is not difficult at all. Locate one of them and find how many electron dense regions there are. Phosphorous in this diagram has 3 single bonds and one lone pair so it h...
- Sun Nov 29, 2020 8:45 pm
- Forum: Hybridization
- Topic: Sapling #12
- Replies: 27
- Views: 182
Re: Sapling #12
When you're trying to find the hybridization orbitals just look for the amount of electron dense areas. C and O in that problem have 4 areas so you get sp3 because sp3 has 4 areas of electron density, S P P P being the 4 different orbitals that can have electrons.
- Sun Nov 29, 2020 8:41 pm
- Forum: Hybridization
- Topic: delocalized pi bonds
- Replies: 15
- Views: 70
Re: delocalized pi bonds
Delocalized pi bonds always happen with resonance of atoms that have multiple bonds, typically double bonds. They are also in a circular pattern such as a hexagonal shape, so if you have a carbon chain with the same amount of hydrogen chances are you have delocalized pi bonds.
- Sun Nov 29, 2020 8:35 pm
- Forum: Hybridization
- Topic: Definition of Hybridization
- Replies: 5
- Views: 59
Re: Definition of Hybridization
Hybridization is the explanation of what happens when you combine atoms to form a molecule. The bonds between atoms make hybridized orbitals because these atoms are being shared. There is no easy way to do it unless you practice and practice and you recognize molecules and their valence electrons by...
- Sun Nov 29, 2020 8:33 pm
- Forum: Hybridization
- Topic: Hybridization of Carbon
- Replies: 10
- Views: 83
Re: Hybridization of Carbon
The 3 from the sp3 comes from the 3 atomic orbitals that p has. For example D has 5 orbitals and f has 7 as well as s having one. S does not have a number because the one is just one so its just S.
- Sun Nov 22, 2020 7:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle of Molecule
- Replies: 7
- Views: 42
Re: Bond Angle of Molecule
You got the answer correct because you chose the experimental value of the degrees when you have 2 lone pairs and 2 bonds. So both answers were acceptable.
- Sun Nov 22, 2020 7:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 6
- Views: 37
Re: Lone Pairs
Lone pairs are diffuse in the sense they repulse each other more than bonding pairs. That is why the lone pairs affect the shape of some molecules because they repulse the bonding pairs so much.
- Sun Nov 22, 2020 6:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape
- Replies: 10
- Views: 57
Re: Shape
Since it has only bond its shape would be linear.
- Sun Nov 22, 2020 6:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: CH3F Molecular Shape
- Replies: 7
- Views: 60
Re: CH3F Molecular Shape
CH3F is tetrahedral, the fluorine however affects the bond angle. I am not sure how much it changes it.
- Sun Nov 22, 2020 6:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 21
- Views: 106
Re: Bond Angles
You cannot determine bond angles from any molecular structure. You have to search it up because they are experimentally determined, but you can memorize them.
- Sun Nov 15, 2020 11:27 am
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity difference
- Replies: 12
- Views: 89
Re: Electronegativity difference
You can calculate it if you are given the table during a test. But you can always recognize ionic vs covalent by using the electronegativity trend. The most electronegativity is top right and the least being bottom left. So use this trend, and when elements are further away from each other you'll se...
- Sun Nov 15, 2020 11:24 am
- Forum: Dipole Moments
- Topic: Sapling number 17
- Replies: 10
- Views: 78
Re: Sapling number 17
CH4 exhibits LDF only because it is non polar. The reason why is because all the hydrogens have the same bond with the carbon and have the exact same pull. So there is induced dipole but there is nothing else.
- Sun Nov 15, 2020 11:20 am
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 19
- Views: 100
Re: Resonance
The reason why resonance lowers energy is due to the double bond that there is. Because of a bond having resonance, all the bond lengths become shorter due to partial bond lengths. Basically, now all the bonds are shorter because of the resonance.
- Sun Nov 15, 2020 11:16 am
- Forum: Octet Exceptions
- Topic: Identifying Radicals
- Replies: 24
- Views: 175
Re: Identifying Radicals
The easiest way to identify a radical is to first count the amount of valence electrons. Once you do this, anytime you have an odd amount of electrons, it is a radical. But often, they can be balanced you may have just forgot to add or subtract electrons according to the charge.
- Sun Nov 15, 2020 11:15 am
- Forum: Octet Exceptions
- Topic: Valence electrons for Beryllium
- Replies: 2
- Views: 27
Re: Valence electrons for Beryllium
Beryllium will want to lose electrons and have 2 valence electrons. Beryllium is a cat anion and so to achieve a full outer shell, it will lose electrons from 2s2 to get to 1s2.
- Sun Nov 08, 2020 7:47 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma vs. Pi
- Replies: 20
- Views: 468
Re: Sigma vs. Pi
Sigma bonds are much stronger because when they overlap each other, they have a higher strength. While Pi bonds are side by side thus having less connection and much less strength.
- Sun Nov 08, 2020 7:45 pm
- Forum: Electronegativity
- Topic: Noble Gases
- Replies: 40
- Views: 1750
Re: Noble Gases
Noble gases have a full valence electron shell, so they do not pair with anything unless electrons are forced onto it. Which requires quite a bit of energy and the electron is lost rapidly.
- Sun Nov 08, 2020 7:42 pm
- Forum: Lewis Structures
- Topic: Lewis Dot Structure
- Replies: 11
- Views: 86
Re: Lewis Dot Structure
When you are doing a lewis dot structure for one independent atom, then you put the electrons according to the outer shell of valence electrons. The order is typically one dot clockwise at each spot until you use all of your electrons. Say you have 5 electrons in the other shell which would be nitro...
- Sun Nov 08, 2020 7:41 pm
- Forum: Ionic & Covalent Bonds
- Topic: Identifying Ionic and Covalent Bonds
- Replies: 10
- Views: 39
Re: Identifying Ionic and Covalent Bonds
As people above have said, when you calculate the electronegativity, when it is above 2 it is a covalent bond and below 1.5 it is a ionic bond.
- Sun Nov 08, 2020 7:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: Size of Bonds
- Replies: 28
- Views: 99
Re: Size of Bonds
Due to the weaker connection of having 2 electrons in a single compared compared to a double bond with 4 electrons, the double bond is shorter because there are more protons in the double bond compared to the single bond.
- Sun Nov 01, 2020 7:05 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: The equation
- Replies: 7
- Views: 62
Re: The equation
Any time you have a question that either gives or asks for the indeterminacy for velocity or position, then you know you will be using the Heisenberg Equation.
- Sun Nov 01, 2020 7:03 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbital vs. Subshell
- Replies: 13
- Views: 93
Re: Orbital vs. Subshell
S, P, D, and F are all subshells and within each sub shell you have an amount of orbitals. In S there is one orbital which has 2 electrons, P has 3 orbitals that can have 6 electrons, D has 5 orbitals which can have 10 electrons and finally f has 7 orbitals which can have a total of 14 electrons.
- Sun Nov 01, 2020 7:01 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Sapling #24
- Replies: 16
- Views: 73
Re: Sapling #24
Wave lengths can have no discrepancies. They have to have a consistent amplitude and wavelength, if these differ then it will not be correct. Also it must start from the top and end at the bottom for it to count as a wavelength.
- Sun Nov 01, 2020 7:00 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals and Electrons
- Replies: 9
- Views: 40
Re: Orbitals and Electrons
The Pauli Exclusion Principle states that orbitals can only have a maximum of 2 electrons per orbital and they almost must have opposing spins.
- Sun Nov 01, 2020 6:59 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 4s and 3d
- Replies: 14
- Views: 104
Re: 4s and 3d
Always remember except for rare cases that electrons will always fill lower levels before they move onto higher levels. 4s is a higher energy level than 3d, hence the reason 3d fills first.
- Sun Oct 25, 2020 2:48 pm
- Forum: Photoelectric Effect
- Topic: Mass of atoms
- Replies: 18
- Views: 105
Re: Mass of atoms
Mass of atoms should always be in Kilograms. When it comes to electrons, neutrons and protons all are on the formula sheet, so you will know the masses of all the following. So undoubtedly you will not get the mass of any of these particles in anything but kilograms.
- Sun Oct 25, 2020 2:47 pm
- Forum: Photoelectric Effect
- Topic: Intensity vs. Frequency
- Replies: 22
- Views: 140
Re: Intensity vs. Frequency
Frequency is the amount of waves that are being sent in a period of time. Intensity is the light that can increase but the photons rendered in light can increase which is how intensity increases.
- Sun Oct 25, 2020 2:40 pm
- Forum: DeBroglie Equation
- Topic: Using kg in DeBroglie Equation instead of g
- Replies: 3
- Views: 37
Re: Using kg in DeBroglie Equation instead of g
Planck's constant which is 6.626 times ten to the negative thirty fourth power has Joules. To cancel the joules, which is kilogram times m2 and s-2. This Kg needs to be removed to find the final frequency. You can only do this by having Kg at the denominator.
- Sun Oct 25, 2020 2:38 pm
- Forum: DeBroglie Equation
- Topic: Purpose of DeBroglie Equation
- Replies: 11
- Views: 114
Re: Purpose of DeBroglie Equation
The purpose of the De Broglie equation is supposed to find the wave like function of small atoms. You can use momentum with Planck's constant to find the frequency of a small particle.
- Sun Oct 25, 2020 2:36 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: #26 in sapling
- Replies: 3
- Views: 20
Re: #26 in sapling
First things first remember when you're finding the molar mass from a mol you have to initially use avogadros number to convert to grams. Then from grams convert to kilograms!
- Sat Oct 17, 2020 3:49 pm
- Forum: Einstein Equation
- Topic: Planck's Number
- Replies: 6
- Views: 108
Re: Planck's Number
Plancks constant which is 6.626 x 10 to the negative 34th power joules which is the electromagnetic radiation divided by frequency. This helps you find several other key parts of the Quantum World.
- Sat Oct 17, 2020 3:47 pm
- Forum: Einstein Equation
- Topic: m vs nm
- Replies: 66
- Views: 438
Re: m vs nm
Meters is usually best, but nano meters works just as well for the final answer. You just have to make sure you're using scientific notation properly and you convert. Either works but more importantly focus on converting correctly.
- Sat Oct 17, 2020 3:46 pm
- Forum: Properties of Light
- Topic: Textbook Self Test 1b.3a
- Replies: 3
- Views: 28
Re: Textbook Self Test 1b.3a
Hello, once you have solved for the energy you have to find the longest wavelength of radiation which is the equation, I=hv. The I is the energy required to eject an electron, and the H being Planck's constant and V the wavelength.
- Sat Oct 17, 2020 3:42 pm
- Forum: Properties of Electrons
- Topic: Work function/Threshold Energy
- Replies: 19
- Views: 91
Re: Work function/Threshold Energy
Absolutely, work function and threshold energy are directly related. The work function is the amount of energy it takes to release an electron from a material, and the threshold energy is that amount of energy. Once the material passes that threshold of energy it immediately releases an electron.
- Sat Oct 17, 2020 3:40 pm
- Forum: Student Social/Study Group
- Topic: How are you studying?
- Replies: 203
- Views: 1289
Re: How are you studying?
Reading the textbook and taking notes. I write down all the formulas that are important and highlight them. I complete all the given homework assignments that were labeled in the textbook, and I follow answer that are also given and check my answers and the work behind it.
- Fri Oct 09, 2020 11:38 am
- Forum: SI Units, Unit Conversions
- Topic: Kg to g
- Replies: 13
- Views: 138
Re: Kg to g
If you have 10.6 KG and you're converting to grams just move the decimal 3 places to the right because there are 1000grams in one KG. Its a simple way to do it.
- Fri Oct 09, 2020 11:37 am
- Forum: Significant Figures
- Topic: Which number determines sig figs of the answer?
- Replies: 26
- Views: 179
Re: Which number determines sig figs of the answer?
When you are multiplying it is determined by the number with the least amount of significant digits.
- Fri Oct 09, 2020 11:29 am
- Forum: Balancing Chemical Reactions
- Topic: Fractions
- Replies: 26
- Views: 169
Re: Fractions
You should not have fractions when balancing a chemical equation, so anytime that you see a fraction such as 3/4, multiply by its denominator, and then find out how many molecules you have of each and then proceed to balance the equation again, be careful because you might have to multiply by a mult...
- Fri Oct 09, 2020 11:27 am
- Forum: Balancing Chemical Reactions
- Topic: How moles should be balanced on each side
- Replies: 11
- Views: 65
Re: How moles should be balanced on each side
Its very important to look strictly at the amount of moles you have. It helps you count each side individually and them multiplying it out and seeing what you get in order to balance the full equation. There are 4 H's on the left therefore there must be 4 on the right side as well.
- Fri Oct 09, 2020 11:24 am
- Forum: Empirical & Molecular Formulas
- Topic: Rounding up for Empirical Formulas?
- Replies: 10
- Views: 103
Re: Rounding up for Empirical Formulas?
Confirming what many other students have posted, but you should not round until the final answer, I typically use 4-5 numbers to the right of the decimal if they are present and then round once I get to my final answer according to what the question requires.
- Fri Oct 09, 2020 11:21 am
- Forum: Empirical & Molecular Formulas
- Topic: difference between empirical and molecular
- Replies: 15
- Views: 70
Re: difference between empirical and molecular
Empirical formula sets the varying ratios of molecules to make up a formula while the molecular formula specify the specific amount of each molecule.