Oxygen, liquid, caution

A liquid perfluorocarbon was being used as solvent in an oxidation by oxygen under pressure more energy was released than expected [1], It is cautioned that fluorocarbons are not inert to oxidation, presumably to carbonyl fluoride. An explosion has been experienced with perfluorotoluene in like circumstances [2], A correspondent reports that perfluorotoluene is flammable in air, more saturated perfluorocarbons in pure oxygen [3], Another detailed the combustion performance of polytetrafluoroethylene 148 kcal/mole ignition temperature not below 465°C at 7000 psi of oxygen [4], the product is mostly carbonyl fluoride. Other oxidants may also present a risk in extreme circumstances. 

Caution. PMe3 is an oxygen-sensitive, flammable liquid PBz3 is an irritant. These phosphines are best stored in an inert atmosphere glovebox. The 1.0 M PMe3 solution in toluene is recommended. 

To start a vacuum system such as that illustrated in Fig. 5.1, the clean main trap is fitted in place with an even coat of stopcock grease on the joint. A Dewar partially filled with liquid nitrogen is raised around this trap, and the fore pump is immediately turned on. CAUTION Oxygen from the atmosphere will condense in a trap heid at liquid nitrogen temperature therefore, it Is important never to leave a trap cooled to liquid nitrogen temperature exposed to the atmosphere for a significant length of time. When the line has pumped down to less than 1 torr, the... 

Caution. In order to present air from accidentally entering the system, stop the addition of SiCU EtiO sotution while a small amount of liquid is still present in the addition funnel. This is important since silane will inflame or explode upon exposure to oxygen. 

In view of the action of trace impurities, many early observations on product distributions and on quantum yields in photolysis studies should be regarded with caution, particularly in the case of solution or liquid phase in which the reaction behaviour is extremely sensitive to traces of oxygen . ... 

Caution. Triethylaluminum is a pyrophoric liquid that reacts violently with water or alcohols. It should be handled only in a rigorously oxygen- and moisture-free atmosphere, using face shield and gloves. The solution of triethylaluminum in toluene is most conveniently... 

Most dialkylhaloboranes as well as the trialkylboranes are liquid and are oxidized rapidly by atmospheric oxygen. ( Caution. Boranes with high vapor pressures such as chlorodiethylborane are spontaneously flammable.) The B-haloboranes are easily hydrolyzed. Therefore, in all experiments, air and moisture must be excluded by operation under an inert gas (N2, Ar). 

Yellowish, transparent, flammable liquid penetrating fragrant, somewhat fruity odor. Unstable and dec on exposure to air and light. The pure nitrite has d 0.875. bp 97-99. but volatilizes readily at much lower temps, ng 1.3871. Very slightly sol in water miscible with ale, chloroform, ether. Caution Forms an explosive mixture with air or oxygen. Keep in tightly closed containers protected from light and in cool place. Incompat Alcohol, antipyrine, caustic alkalies, alkaline carbonates, potassium iodide, bromides, ferrous salts. 

Cryomicrotome with microtome blades (e.g., Shandon Cryostat, Thermo Fisher Scientific), frozen specimen embedding medium (FSEM, Shandon Cryomatrix, Thermo Fisher Scientific, Inc., Waltham, MA, USA), and liquid N2. CAUTION It causes suffocation when present at amounts sufficient to reduce oxygen concentration below 19.5%. Contact with tissue can cause severe cryogenic burns. Always handle with protective gloves. 

Caution Liquid oxygen, if spilled on clothing or another combustible substance, can pose a serious hazard of fire or explosion due to the rapid chemical reaction between the two substances. 

Caution Liquid oxygen, if spilled on clothing or another combustible substance, can pose a serious hazard of fire or explosion due to the rapid chemical reaction between the two substances. If liquid oxygen is spilled on clothing, the clothing must be removed at once and aired before reuse. Areas where liquid oxygen may be spilled during transfer operations must be free of hycrocarbons or other combustible materials. 

An estimation of the mass transfer coefficients (Kq, Xl), the mass transfer area (fly), and the volume fractions of gas and liquid (ec, el) can be carried out with the correlation equations, which have been developed on the basis of hydrodynamical theories and dimension analysis. The constants incorporated into the equations have subsequently been determined on the basis of experimental data for a number of model systems (such as air-water, oxygen-water, etc.). The dependability of these correlation equations can thus be very different. Usually, the quality of the estimations falls somewhere around 10-30% of the actual values. The correlations presented in the literature should therefore be utilized with great caution, and the validity limitations should be carefully analyzed. However, these correlations are very useful, for example, when performing feasibility studies or planning one s own experimental measurements. A thorough summary of various correlation equations for gas-Kquid reactors is presented by Myllykangas [ 1 ]. Here we will only treat two common gas-Kquid reactors, namely, bubble columns and packed columns, operating in a countercurrent mode. 

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