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Vapor Pressure: The contribution to barometric Pressure of gaseous substance in equilibrium with its solid or liquid phase.

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

1Joint Center for Artificial Photosynthesis, Chemical Sciences Division, Lawrence Berkeley National Laboratory, 2Electrical Engineering and Computer Sciences, University of California, Berkeley, 3Materials Science Division, Lawrence Berkeley National Laboratory, 4Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, 5Department of Physics, Graduate School of Nanotechnology, University of Trieste, 6TASC Laboratory, IOM-CNR - Istituto Officina dei Materiali, 7Department of Chemistry, University of California, Berkeley, 8Materials Science and Engineering, University of California, Berkeley, 9Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory

JoVE 55404


 Chemistry

Quantitative Detection of Trace Explosive Vapors by Programmed Temperature Desorption Gas Chromatography-Electron Capture Detector

1Chemical Sensing & Fuel Technology, Chemistry Division, U.S. Naval Research Laboratory, 2NOVA Research, Inc., 3Bio/Analytical Chemistry, Chemistry Division, U.S. Naval Research Laboratory, 4Navy Technology Center for Safety and Survivability, Chemistry Division, U.S. Naval Research Laboratory

JoVE 51938


 Chemistry

Conducting Miller-Urey Experiments

1School of Chemistry and Biochemistry, Georgia Institute of Technology, 2Earth-Life Science Institute, Tokyo Institute of Technology, 3Institute for Advanced Study, 4Astromaterials Research and Exploration Science Directorate, NASA Johnson Space Center, 5Goddard Center for Astrobiology, NASA Goddard Space Flight Center, 6Geosciences Research Division, Scripps Institution of Oceanography, University of California at San Diego

JoVE 51039


 Chemistry

Fractional Distillation

JoVE 5700

Source: Laboratory of Dr. Nicholas Leadbeater — University of Connecticut 

Distillation is perhaps the most common laboratory technique employed by chemists for the purification of organic liquids. Compounds in a mixture with different boiling points separate into individual components when the mixture is carefully distilled. The two main types of distillation are "simple distillation" and "fractional distillation", and both are widely used in organic chemistry laboratories. Simple distillation is used when the liquid is (a) relatively pure (containing no more than 10% liquid contaminants), (b) has a non-volatile component, such as a solid contaminant, or (c) is mixed with another liquid with a boiling point that differs by at least 25 °C. Fractional distillation is used when separating mixtures of liquids whose boiling points are more similar (separated by less than 25 °C). This video will detail the fractional distillation of a mixture of two common organic solvents, cyclohexane and toluene.


 Organic Chemistry

Utilization of Capsules for Negative Staining of Viral Samples within Biocontainment

1Pathology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), 2Diagnostic Systems Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), 3Microscopy Innovations LLC

JoVE 56122


 Immunology and Infection

Optimal Preparation of Formalin Fixed Samples for Peptide Based Matrix Assisted Laser Desorption/Ionization Mass Spectrometry Imaging Workflows

1Mass Spectrometry Core Facility, University of Sydney, 2Proteomics Core Facility, University of Technology Sydney, 3Neuropathology Group, Discipline of Pathology, School of Medical Sciences, University of Sydney, 4Redox Biology Group, Discipline of Pathology, School of Medical Sciences, University of Sydney

Video Coming Soon

JoVE 56778


 JoVE In-Press

A Detailed Protocol for Perspiration Monitoring Using a Novel, Small, Wireless Device

1Wellness Promotion Science Center, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 2Advanced Research Center for Human Sciences, Waseda University, 3Department of Clinical Laboratory Science, Graduate School of Medical Science, Kanazawa University, 4Asanogawa General Hospital

JoVE 54837


 Medicine

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

1SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, 2Department of Physics, National University of Singapore, 3NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, 4Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore

Video Coming Soon

JoVE 57023


 JoVE In-Press

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

1Department of Physics, University of California at Berkeley, 2Department of Chemistry, University of California at Berkeley, 3Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 4National Institute for Materials Science (Japan), 5Materials Sciences Division, Lawrence Berkeley National Laboratory, 6Kavli Energy NanoSciences Institute, University of California at Berkeley and Lawrence Berkeley National Laboratory

JoVE 52711


 Engineering

Determining Rate Laws and the Order of Reaction

JoVE 10193

Source: Laboratory of Dr. Neal Abrams — SUNY College of Environmental Science and Forestry

All chemical reactions have a specific rate defining the progress of reactants going to products. This rate can be influenced by temperature, concentration, and the physical properties of the reactants. The rate also includes the intermediates and transition states that are formed but are neither the reactant nor the product. The rate law defines the role of each reactant in a reaction and can be used to mathematically model the time required for a reaction to proceed. The general form of a rate equation is shown below:     where A and B are concentrations of different molecular species, m and n are reaction orders, and k is the rate constant. The rate of nearly every reaction changes over time as reactants are depleted, making effective collisions less likely to occur. The rate constant, however, is fixed for any single reaction at a given temperature. The reaction order illustrates the number of molecular species involved in a reaction. It is very important to know the rate law, including rate constant and reaction order, which can only be deter


 General Chemistry

Schlenk Lines Transfer of Solvents

JoVE 5679

Source: Hsin-Chun Chiu and Tyler J. Morin, laboratory of Dr. Ian Tonks—University of Minnesota Twin Cities

Schlenk lines and high vacuum lines are both used to exclude moisture and oxygen from reactions by running reactions under a slight overpressure of inert gas (usually N2 or Ar) or under vacuum. Vacuum transfer has been developed as a method separate solvents (other volatile reagents) from drying agents (or other nonvolatile agents) and dispense them to reaction or storage vessels while maintaining an air-free environment. Similar to thermal distillations, vacuum transfer separates solvents by vaporizing and condensing them in another receiving vessel; however, vacuum transfers utilize the low pressure in the manifolds of Schlenk and high vacuum lines to lower boiling points to room temperature or below, allowing for cryogenic distillations. This technique can provide a safer alternative to thermal distillation for the collection of air- and moisture-free solvents. After the vacuum transfer, the water content of the collected solvent can be tested quantitatively by Karl Fischer titration, qualitatively by titration with a Na/Ph2CO solution, or by 1H NMR spectroscopy.


 Organic Chemistry

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