Classic ChemBalancer - Welcome This is the classic version of Chembalancer that teaches you how to balance equations for the first time. To play it, just press the "Start Game" button above. To play the other versions, click here. Teachers: Classic Chembalancer is for students who are learning to balance equations for the first time. If you wish to purchase a version without Google advertisements, please go to Awards for original Classic Chembalancer site © 2005 Sulan Dun. Chemistry Review Activities I re-organized the course during the 2014 - 2015 school year. Some review activities were moved to new units. This has resulted in a change to some of the file names, so direct links to the individual activities may need to be changed. These are not graded assignments. They are intended only as practice of concepts and vocabulary that are essential to your success in this course. Unit 0 - The Methods of Chemistry Unit 1 - Atomic Structure Unit 2 - Periodic Behavior and Ionic Bonding Element Classes Review - Unit 2 Benchmark #1 (Matching Activity) Element Classes Review 2 - Unit 2 Benchmark #1 (Multiple Choice) Element Classes Review - Unit 2 Benchmark #1. Unit 3 - Covalent Bonding and Molecular Structure Lewis Structures - Unit 3 Benchmark #1 Lewis Structures #2 - (HTML5/ Mobile Compliant)Binary Covalent Nomenclature - Writing formulas using names, and writing names using formulas. Unit 4 - Conservation of Matter First Semester Review Semester 1 Millionaire Game. Unit 6 - Water
Elemental Analysis Tutorial and Quiz Using the above measurements and the power of math, we will come up with a formula for glucose. As usual we can't count atoms, but we can measure their mass. Here we have measured the mass of water absorbed by measuring the before and after weights of the MgSO4 canister. Then we can convert that to a count of hydrogen atoms: The increase of mass in MgSO4 canister is just from H2O. The canister's start weight was from the canister itself plus an unknown mass of the NaOH inside. Let N be the starting grams of NaOH. Canister after glucose burned: 241.8 g = C + N + S - M Canister with NaOH start weight: 155.2 g = C + N Subtracting the the start weight from the end weight: 86.6 g=(C+N+S-M) - (C+N) = S - M This shows that the difference in weight is the grams of Na2CO3 created minus the grams of NaOH converted. Y=3.33 moles of Na2CO3 There is one carbon for each molecule of Na2CO3, so that means there are also 3.33 moles of carbon in this 100.0g sample of glucose. Now we are almost there.
Periodic Table of Elements and Chemistry Chemical & Engineering News: What's That Stuff? You might ask yourself... What's That Stuff? Ever wondered about what's really in hair coloring, Silly Putty, Cheese Wiz, artificial snow, or self-tanners? Sort: Alphabetically (Text Only) | Most Recent Theoretical Yield The theoretical yield of a reaction is the amount of product that would be formed if the reaction went to completion. It is based on the stoichiometry of the reaction and ideal conditions in which starting material is completely consumed, undesired side reactions do not occur, the reverse reaction does not occur, and there no losses in the work-up procedure. Theoretical yield calculations are carried out in the same way as they were in general chemistry: the moles of limiting reactant determines the moles of product. Balance the reaction and determine the stoichiometry or ratios of reactants to products. After your laboratory reaction is complete, you will isolate and measure the amount of product, then compare the actual yield to the theoretical yield to determine the percent yield: In the laboratory, the percent yield has the practical aspect of telling you how successful was your synthesis scheme. Example Calculations of Theoretical and Percent Yield Example 4: mass = volume x density
AP Chemistry Review Activities AP Chemistry Interactive Review Activities In keeping with the new framework for AP Chemistry beginning in 2013 - 2014, I am indicating here if the topic to which a review activity relates has been dropped from the curriculum. It will be identified as excluded (Excluded) to indicate that the College Board has specifically excluded it. These are not graded assignments. Each time you reload the activity, the problems will be in a different order, and the answers will be reshuffled!
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How Buffers Work How does a mixture of a weak acid and its conjugate base help buffer a solution against pH changes? If we mix a weak acid (HA) with its conjugate base (A-), both the acid and base components remain present in the solution. This is because they do not undergo any reactions that significantly alter their concentrations. The acid and conjugate base may react with one another, HA + A- → A- + HA, but when they do so, they simply trade places and the concentrations [HA] and [A-] do not change. In addition, HA and A- only rarely react with water. By definition, a weak acid is one that only rarely dissociates in water (that is, only rarely will the acid lose its proton H+ to water). So, the weak acid and weak base remain in the solution with high concentrations since they only rarely react with the water. If a strong base is added to a buffer, the weak acid will give up its H+ in order to transform the base (OH-) into water (H2O) and the conjugate base: HA + OH- → A- + H2O.
Chemistry | 5.112 Principles of Chemical Science, Fall 2005 | Video Lectures | Lecture 26: Molecular Orbital Theory Top 10 Amazing Chemistry Videos | Wired Science Fiery explosions, beautiful reactions, and hilarious music videos are great reasons to be excited about chemistry. Here are some of our favorites. 10. 9. 8. 7. 6. 5. 4. 3. 2. 1. If you have not had enough yet, check out the brilliant collection of Edward Kent.
ch03_11 3.11 Solutions and Solution Stoichiometry Many chemical reactions are rapid and reproducible when carried out in the liquid state. As a result, chemists often dissolve solids in a liquid and carry out reactions in a liquid medium. In Chapter 1, we noted that a solution is a homogeneous mixture of two or more substances. The components of a solution are the solute(s)—the substance(s) being dissolved—and the solvent—the substance doing the dissolving. Components of a Solution activity The concentration of a solution refers to the quantity of solute in a given quantity of either solvent or solution. For commercially available acids and bases, the term concentrated generally signifies the highest concentration, usually expressed as a mass percent, that is commonly available. Molar Concentration Mass percent composition, as in 38% HCl by mass, is one way to describe the concentration of a solution, but there are several other ways as well. Solution Formation from a Solid animation and