Finding the Empirical Formula from a Molecular Formula
Elemental analysis is a useful qualitative analysis technique since it allows us to check if a sample is consistent with a given molecular formula. For instance, suppose we believe our sample is benzene (C6H6). We can compare the following:The empirical formula (CH) obtained from the molecular formula of benzene (C6H6); The empirical formula obtained from a elemental analysis of the sample. If the two empirical formulae do not agree, then the sample is not benzene. If the formulae agree, then ou
Finding Empirical Formula from an Elementary Analysis
On another page, we discuss how to obtain the empirical formula from a given molecular formula. Here, we consider how to obtain the empirical formula from an elemental analysis of a sample. Remember that comparing the empirical formula obtained from an elemental analysis with that from a molecular formula tells us if the sample is consistent with the molecular formula.
We are now ready to pull everything we know about reaction stoichiometry together, and answer the question: Given some initial amount of reactants, what should be present after a chemical reaction goes to completion? The procedure for answering this question is often called the "limiting reagent problem." You'll see why this name is appropriate in the following video.
You and a friend are hiking the Appalachian Trail when a storm comes through. You stop to eat, but find that all available firewood is too wet to start a fire. From your Chem 106 class, you remember that heat is given off by some chemical reactions; if you could mix two solutions together to produce an exothermic reaction, you might be able to cook the food you brought along for the hike. Luckily, being the dedicated chemist that you are, you never go anywhere without taking along a couple chemi
Mixed Reception Scenario
This activity is set in a research group that is developing an antivenom for spider bites. In the opening scene, Nelson Pogline, a talented graduate student, dies unexpectedly at a university reception. As a detective, you must use chemistry concepts to determine if this was murder and if so, solve the case. You can interview suspects using Quicktime movies, investigate the crime scene for clues with Quicktime Virtual Reality images, and analyze the evidence from the crime lab. This activity req
During the first kinetics lecture, we traced the efforts of atmospheric chemists to explain the depletion of ozone in the upper atmosphere. (The powerpoint slides have been posted on Blackboard for your review.) U2 spy planes gathered much of the initial data that linked ClO in the stratosphere to the ozone depletion. The data collected during these flights showed the concentrations of various chemical species in the stratosphere, but did not measure how fast the processes were occurring. To det
Product Formation and Percent Yield
In another tutorial, we considered the amount of reactant consumed by a chemical reaction. Here, we'll consider the amount of product formed by a reaction.
Reaction stoichiometry allows us to determine the amount of substance that is consumed or produced by a reaction. The following video considers the first part of this: how much of a reactant is consumed in a chemical reaction. Product formation is discussed elsewhere.
Step by Step Glycolysis
You can browse the eleven steps of anaerobic glycolysis and view three kinds of information: reaction data (the enzyme, reaction type and thermodynamic data), equation and animation. Glükoosi anaeroobne lagundamine etappide kaupa. Üleminekud, reaktsiooni vaheühendid, üldinfo ning lühike animatsioon molekulimudelitega. Sobib ainevahetuse käsitlemisel üldbioloogias. You can browse the eleven steps of anaerobic glycolysis and view three kinds of information: reaction data (the enzyme, rea
Step by Step Krebs cycle
These pages show the steps of the metabolic pathway called the Tricarboxylic Acid (TCA) cycle. Otherwise known as the citric acid cycle and the Krebs cycle. Data sheets, reaction diagrams and animations are provided for each step. Krebs cycle or the citric acid cycle or tricarboxylic acid cycle,occurs in mitochondria, is the common pathway to completely oxidize fuel molecules which mostly is acetyl CoA ,the product from the oxidative decarboxylation of pyruvate. It enters the cycle and passes
Lennard-Jones Potential Model
The EJS Lennard-Jones Potential model shows the dynamics of a particle of mass m within this potential. You can drag particle to change its position and you can drag the energy-line to change its total energy. The Lennard-Jones potential function is a reasonably accurate model of interactions between noble gas atoms. The binding energy epsilon is the depth of the potential well and minimum molecular separation are set equal to unity. This simulation uses uses a natural system of units the m
Anisotropic Oscillator Model
The EJS Anisotropic Oscillator model displays the dynamics of a mass connected to two opposing springs. The simulation displays the motion of the mass as well as the trajectory plot. The initial position of the mass can be changed by dragging. The unstretched lengths of the springs can changed as well via textboxes.
This set of lecture notes covers a number of topics including magmatic differentiation, chemical variation in rock suites, partial melting, fractional melting, crystal fractionation, Bowen's reaction series, and magma mixing. Graphs discussed include oxides vs. SiO2, and MgO vs. SiO2. The notes are ...
Metamorphic Reactions, Isograds, and Reaction Mechanisms
These lecture notes cover types of metamorphic reactions. Topics discussed include univariant and divariant reactions, mineral compatibility diagrams (AFM ternary), metamorphic reaction mechanisms, and metamorphic field gradients. The notes contain many ternary diagrams and graphs illustrating the relationship ...
"Neuropharmacology, January IAP 2009"
" The neuropharmacology course will discuss the drug-induced changes in functioning of the nervous system. The specific focus of this course will be to provide a description of the cellular and molecular actions of drugs on synaptic transmission. This course will also refer to specific diseases of the nervous system and their treatment in addition to giving an overview of the techniques used for the study of neuropharmacology. This course is offered during the Independent Activities Period (IAP)
"Electromechanical Dynamics, Spring 2009"
" First published in 1968 by John Wiley and Sons, Inc., Electromechanical Dynamics discusses the interaction of electromagnetic fields with media in motion. The subject combines classical mechanics and electromagnetic theory and provides opportunities to develop physical intuition. The book uses examples that emphasize the connections between physical reality and analytical models. Types of electromechanical interactions covered include rotating machinery, plasma dynamics, the electromechanics o
"Global Enterprise for Micro-Mechanics and Molecular Medicine (GEM4), Summer 2006"
"GEM4 VisionGEM4 has brought together researchers and professionals in major institutions across the globe with distinctly different, but complementary, expertise and facilities to address significant problems at the intersections of select topics of engineering, life sciences, technology, medicine and public health.GEM4 creates new models for interactions across scientific disciplinary boundaries whereby problems spanning the range of fundamental science to clinical studies and public health ca
This book addresses the following topics: Iterations and fixed points; bifurcations; conjugacy; space and time averages; the contraction fixed point theorem; Hutchinson's theorem and fractal images; hyperbolicity; and symbolic dynamics. 151 page pdf file.
Normalization of relations with Communist China
Following on from President Carter's December 15, 1978 announcement recognizing the People's Republic of China and the establishment of diplomatic relations, Evelyn Wong looks into the divided reaction of Boston's Chinese American community to United States-China normalization. Peter H.F. Wong, President of the New England Chinese Consolidated Benevolent Association, thinks the normalization of relations is entirely inappropriate.
Northern Fur Seal Information
This National Marine Mammal Laboratory website provides links to detailed information about the distribution of fur seals in the Bering Sea region. It also features related links that lead to maps of fur seal rookeries on St. Paul Island and St. George Island, as well as PDF reports that describe fur seal population dynamics from 1993-2001.