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Видео добавленное пользователем “chemistNATE”
Which way will the Equilibrium Shift? (Le Chatelier's Principle)
 
08:31
Check me out: http://www.chemistnate.com
Просмотров: 407269 chemistNATE
How to Find the Abundance of Each Isotope
 
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If you're given the mass of each isotope of an element, and the average atomic mass, you can calculate the percent (%) abundance of each isotope. Let "x" be one of the abundances, and the other abundance is "1-x" ... then solve the equation using basic algebra.
Просмотров: 711314 chemistNATE
How to Draw Bohr-Rutherford Diagrams - Potassium
 
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How to draw the Bohr-Rutherford Diagram for Potassium. 2 electrons can go in the first shell, 8 in the second, 8 in the third, and so on...
Просмотров: 170201 chemistNATE
Find the Empirical Formula Given Percents
 
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If you're given the Percent Composition of a compound, you can find the Empirical Formula for it. I have the shortest method ever to do it, although it's not a "full solution" like your teacher probably asks for. 1. Divide each % by the atomic mass of the element 2. Divide each of THOSE answers by whatever's smallest 3. Adjust these numbers into their lowest whole-number ratio. Check me out: http://www.chemistnate.com
Просмотров: 572937 chemistNATE
Sigma and Pi Bonds: Hybridization Explained!
 
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Sigma bonds are the FIRST bonds to be made between two atoms. They are made from hybridized orbitals. Pi bonds are the SECOND and THIRD bonds to be made. They are made from leftover "p" orbitals. Check me out: http://www.chemistnate.com
Просмотров: 1218454 chemistNATE
Find the Ka Using a Titration Curve
 
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The pKa of an acid is exactly the same as the pH HALFWAY to the equivalence point! Then, Ka = 10^-pKa and you're done. Super easy. Thanks Henderson-Hasselbalch! Check me out: http://www.chemistnate.com
Просмотров: 240822 chemistNATE
How to Find Significant Figures (Easy Method)
 
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How many significant figures are in a number? Don't memorize complex rules ... here's THREE that will get you the right answer each time.
Просмотров: 221170 chemistNATE
Identify Conjugate Acid Base Pairs (Bronsted Lowry)
 
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Use Bronsted Lowry Acid/Base Theory to identify conjugate acid base pairs. More free chemistry help at www.chemistnate.com
Просмотров: 426350 chemistNATE
How to Draw Bohr-Rutherford Diagrams - Phosphorous
 
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How to draw the Bohr-Rutherford Diagram for Phosphorous. 2 electrons can go in the first shell, 8 in the second, 8 in the third, and so on...
Просмотров: 69010 chemistNATE
Find the Average Atomic Mass - Example: Magnesium
 
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How to find the average atomic mass of an element. You need to know the mass of each isotope and the percent (%) abundance of each as well. Multiply each mass by its corresponding percentage, and add these products together.
Просмотров: 320319 chemistNATE
What are the Pauli Exclusion Principle, Aufbau Principle, and Hunds Rule?
 
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What are the Pauli Exclusion Principle, Aufbau Principle, and Hunds Rule? They are rules we use to fill electron orbital filling diagrams. Fill from the bottom up, Spread them out before you double up, and always have one up one down in each orbital.
Просмотров: 429190 chemistNATE
Periodic Trends - What they are, how to remember them
 
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What are the periodic trends? Electronegativity, Atomic Radius, Ionization Energy, and Electron Affinity. How to remember them? F has the highest electronegativity, electron affinity, and one of the largest ionization energies. It is also one of the smallest atoms.
Просмотров: 250771 chemistNATE
Which molecules have higher (or lower) vapor pressure
 
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Stronger intermolecular forces = LOWER vapor pressure Weaker intermolecular forces = HIGHER vapor pressure Check me out: http://www.chemistnate.com
Просмотров: 80877 chemistNATE
How to Write Total and Net Ionic Equations (Easy)
 
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How to write total and net ionic equations. 1. Write a balanced chemical equation 2. Break up all the (aq) compounds into its ions (this is TOTAL) 3. Get rid of spectator ions (things that appear on both sides) (this is NET) Check me out: http://www.chemistnate.com
Просмотров: 782236 chemistNATE
How to Figure out Oxidation Numbers
 
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How to assign oxidation numbers to the atoms in a molecule. 1. Elements have oxidation number = 0 2. Hydrogen's always +1 (except in "hydrides") 3. Oxygen's always -2 (except in "peroxides") 4. Other atoms get the charge they prefer, as long as the sum of oxidation numbers for all atoms = the total charge on the atom.
Просмотров: 714639 chemistNATE
Calculate the pH of a Strong Base
 
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More free chemistry help videos: http://www.nathanoldridge.com/chemistry-videos.html Here I show how to calculate the pH of a solution made with a Strong Base Summary: Use the concentration of base and the number of OH- ions per molecule to calculate the concentration of OH-. Then, you can calculate the pOH as I did, or calculate [H+] since Kw = [H+][OH-] (more on this formula in a later video).
Просмотров: 54382 chemistNATE
Is it an Ionic, Covalent or Polar Covalent Bond?
 
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How to tell if a bond is Ionic, Covalent or Polar Covalent. You have to calculate the difference in electronegativities between the atoms ... the difference tell you which you have!
Просмотров: 215966 chemistNATE
Solubility Equiliibrium (ICE Table and Ksp)
 
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How to use an ICE Table to find the solubility of a salt, if you're given the Ksp. I'll do it on the calculator with you, to show you how to take care of x to the power of 5. Check me out: http://www.chemistnate.com
Просмотров: 158702 chemistNATE
What is the hybridization of each atom in this molecule?
 
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More free chemistry help videos: http://www.nathanoldridge.com/chemistry-videos.html This is the easiest way to figure out how each atom's orbitals are hybridized.
Просмотров: 186788 chemistNATE
Balance a Redox Reaction (BASIC solution)
 
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How to balance a redox reaction in basic solution. Same process as balancing in acidic solution, with one extra step: 1. Make sure electrons gained = electrons lost 2. Add H2O to whichever side doesn't have enough O 3. Add H+ to whichever side doesn't have enough H 4. Add OH- to both sides. These combine with H+ to form H2O.
Просмотров: 313344 chemistNATE
ICE Tables for Equilibrium
 
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Use ICE Tables to figure out equilibrium concentrations. In this example, I use the quadratic formula to solve. There are simplifications you can make, like the Rule of 100, but I don't talk about that here. Check me out: http://www.chemistnate.com
Просмотров: 298422 chemistNATE
Esters: Naming + Properties
 
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Esters are molecules connected by a =O on one carbon, and a -O- on the SAME carbon. The carbon chain is broken into two bits, so each gets its own part of the name. You can identify esters with OATE at the end of the name. They are kinda polar, and them smell fruity. Check me out: http://www.chemistnate.com
Просмотров: 91867 chemistNATE
What is Ksp? (Solubility Product Constant)
 
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Ksp is really just an equilibrium constant (Keq), but it's for a solid dissolving in water. This is special, since all of the reactants are solid, and so they AREN'T included in the equilibrium expression.
Просмотров: 264252 chemistNATE
What is Hydrolysis? + Examples
 
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Hydrolysis is breaking apart molecules by reacting with water. It can happen in lots of places, but if SOMETHING + water = Two other somethings, they it's hydrolysis. Examples: Breaking apart Esters, Bronsted/Lowry Acids, and ATP. Check me out: http://www.chemistnate.com
Просмотров: 97065 chemistNATE
How to Convert Energy to Wavelength
 
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How to Calculate Wavelength if you're Given the Energy of a photon. Wavelength is Planck's Constant times Speed of Light divided by Energy.
Просмотров: 52794 chemistNATE
Octet Rule Exceptions: ALL OF THEM.
 
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Which atoms can violate the octet rule? The answer is basically all of them. H, Li, Be, B and Al can make do with less than 8. Everything beyond P can have MORE than 8 because of hybridization of "d" orbitals. Basically only C, N, O and F follow this rule. Check me out: http://www.chemistnate.com
Просмотров: 61837 chemistNATE
How to Calculate Molar Mass
 
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Ask me questions on Facebook: http://www.facebook.com/chemistNATE How to Calculate the Molar Mass of elements and molecules Elements: Easy, just look at the periodic table. Molecules: Add up the masses of the atoms that form the compound. For example, an oxygen atom weighs 16.00 g/mol according to the periodic table. So an O2 molecule would weigh 2 x 16.00 g/mol = 32.00 g/mol
Просмотров: 859066 chemistNATE
Lewis Structure of HCN
 
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The Lewis Structure (Lewis Dot Diagram) for HCN. 1. Count electrons 2. Put least electronegative atom in centre 3. Put one electron pair in each bond 4. Fill outer atoms with electrons 5. Move electrons so all atoms (esp. the centre one) has a full octet Check me out: http://www.chemistnate.com
Просмотров: 235261 chemistNATE
How to Convert Energy to Frequency
 
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How to calculate the frequency of a photon, given its energy. Frequency = Energy divided by Planck's Constant
Просмотров: 18659 chemistNATE
Draw the Isomers of hexane (C6H14)
 
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There are 5 isomers of hexane ... here I show how you can come up with all of them. n-hexane; 2-methylpentane; 3-methylpentane; 2,2-dimethylbutane; 2,3-dimethylbutane Check me out: http://www.chemistnate.com
Просмотров: 263258 chemistNATE
How to Draw Bohr-Rutherford Diagrams - Oxygen
 
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How to draw the Bohr-Rutherford Diagram for Oxygen. 2 electrons can go in the first shell, 8 in the second, 8 in the third, and so on...
Просмотров: 48474 chemistNATE
Is it a Spontaneous Reaction? Delta G tells you!
 
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To determine if a reaction is spontaneous, use this formula to find Delta G. Gibbs Free Energy is NEGATIVE for spontaneous reactions. You can also determine above which TEMPERATURE the reaction will be spontaneous. Check it out! Check me out: http://www.chemistnate.com
Просмотров: 140843 chemistNATE
Find the Ka of an acid (Given pH) (0.1 M Hypochlorous acid) EXAMPLE
 
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This video shows how you can calculate the Ka of an acid, if you're given the pH of the solution (and its concentration, of course). It's pretty straightforward if you understand where the Ka expression comes from (Equilibrium). New website! www.chemistnate.com
Просмотров: 127965 chemistNATE
How to Draw Lewis Structures (with example)
 
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Ask me questions on Facebook: http://www.facebook.com/chemistNATE How to Draw Lewis Structures (aka Lewis Dot Diagrams) In this video I explain how to draw simple Lewis Structures, while drawing the Lewis structure for a simple molecule (HCN).
Просмотров: 648968 chemistNATE
How to Convert Moles to Number of Molecules
 
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How to Convert an Amount (in moles) into the number of molecules a sample contains. Just multiply by Avogadro's Number (6.022 x 10^23)!
Просмотров: 134411 chemistNATE
Writing Equilibrium Expressions [NEW 2014]
 
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An updated (i.e. better-looking) video that explains how to create equilibrium expressions (Keq) - Products over Reactants - Coefficients become exponents - Don't include solids or liquids Check me out: http://www.chemistnate.com
Просмотров: 19818 chemistNATE
Derive the Henderson-Hasselblach Equation
 
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How to turn a regular old equilibrium expression into the Henderson-Hasselbalch equation. Uses laws of logarithms! Ask me Questions: http://www.chemistnate.com
Просмотров: 30389 chemistNATE
Calculating Moles from Grams (Mass to Moles)
 
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Ask me questions on Facebook: http://www.facebook.com/chemistNATE How to Calculate the number of moles, given the mass of a substance. n = m / M where n = number of moles m = mass in grams M = molar mass (see http://www.youtube.com/watch?v=F9NkYSKJifs)
Просмотров: 613782 chemistNATE
Convert Number of Molecules into Number of Moles
 
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How to Convert a Number of Molecules into an Amount in Moles. Just divide the number of molecules by Avogadro's Number (6.022 x 10^23)!
Просмотров: 82973 chemistNATE
Calculate pH of a Strong Acid
 
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More free chemistry help videos: http://www.nathanoldridge.com/chemistry-videos.html Here I show how to calculate the pH of a solution made with a strong acid (like HCl, H2SO4, HNO3, HBr, HClO4, HI, etc) Remember to account for how MANY H+ ions come from each molecule ... H2SO4 gives 2 H+ when it dissociates.
Просмотров: 80254 chemistNATE
Half-Life of a Second Order Reaction (Derivation)
 
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What is the expression for Half-Life of a Second Order Reaction? Here, I derive it from the integrated rate law. The answer is t = 1/ (k [A]0) Ask me questions: http://www.chemistnate.com
Просмотров: 32770 chemistNATE
Using Slater's Rules: 3 Examples
 
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Sorry this one's so long. But Slater's rules aren't the easiest things in the world. Summary: For an "s" or "p" electron: Add up 0.35 for each electron in same group; plus 0.85 for each electron in the shell below plus 1.00 for each electron two or more shells lower Then subtract this sum from the atomic number to get Z(eff) For a "d" or "f" electron: Add up 0.35 for each electron in the same group plus 1.00 for every electron in any other lower group Then subtract this sum from the atomic number to get Z(eff) Check me out: http://www.chemistnate.com
Просмотров: 178760 chemistNATE
The Common Ion Effect: Lowers Solubility
 
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Here, I find the solubility of calcium phosphate in phosphoric acid. There's already phosphate in solution, so the solubility of the salt is LOWER. I even use a simplifying assumption to spice things up. Check me out: http://www.chemistnate.com
Просмотров: 65710 chemistNATE
Find the pH of a Buffer Solution
 
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Add some acid. Add some conjugate base. What's the pH? This is the old-school way. You can also use the Henderson-Hasselbalch Equation. In this example I use 0.2 M HF and 0.1 M NaF Check me out: http://www.chemistnate.com
Просмотров: 144464 chemistNATE
Lewis Structure of ClO3- (chlorate anion)
 
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The Lewis Structure (Lewis Dot Diagram) for ClO3- 1. Count electrons 2. Put least electronegative atom in centre 3. Put one electron pair in each bond 4. Fill outer atoms with electrons 5. Move electrons so all atoms (esp. the centre one) has a full octet and so formal charges are minimized (in this case, chlorine can have an EXPANDED OCTET!) Check me out: http://www.chemistnate.com
Просмотров: 125753 chemistNATE
Lewis Structure of N2 (Nitrogen Gas)
 
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How to Draw the Lewis Structure of N2 - with explanation! Check me out: http://www.chemistnate.com
Просмотров: 79306 chemistNATE
How to Convert Wavelength to Frequency
 
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How to Get Frequency from Wavelength. Frequency = Speed of Light divided by wavelength.
Просмотров: 31125 chemistNATE
[Spreadsheet] Find Activation Energy from Temps and Rate Constants
 
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If you have rate constants at different temperatures, you can use Microsoft Excel (or OpenOffice) to find the Activation Energy. The slope of a (ln k) vs (1/T) graph is -Ea/R. So just take the slope, flip the sign, and multiply by 8.314 ... the answer will be in J/mol Check me out: http://www.chemistnate.com
Просмотров: 14154 chemistNATE
Find the pH of a Weak Base (F- aka NaF)
 
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The pH of a weak base. Set up equilibrium and K expression. Use ICE Table. Solve for x, which is [OH-]. Take the negative log to get pOH and then subtract from 14 to get pH. Ask me questions: http://www.chemistnate.com
Просмотров: 37248 chemistNATE