Weighted-average formula

When a preparation of polyvinylpyridine of unknown formula weight was analyzed the retention volume was found to be 8.45. Report the average formula weight for the preparation. 

Health and Safety. Remover formulas that are nonflammable may be used in any area that provides adequate ventilation. Most manufacturers recommend a use environment of 50—100 parts per million (ppm) time weighted average (TWA). The environment can be monitored with passive detection badges or by active air sampling and charcoal absorption tube analysis. The vapor of methylene chloride produces hydrogen chloride and phosgene gas when burned. Methylene chloride-type removers should not be used in the presence of an open flame or other heat sources such as kerosene heaters (8). 

LJsually, OELs are stated as the eight-hour time-weighted average concentration of exposure to a substance in gaseous, vaporous, or suspended form in the air at the workplace. Later on we will give a more precise formula. 

Molecular weight -400 formula weight No data No data 265 (average)... 

FWai,. = weighted average of the major gases formula weights... 

Mallinckrodt analytical reagent, chromium(III) sulfate crystals, Cr2(S04)3(H20)x, were employed. Repeated preparations with this substance have indicated its average formula weight to be 542. 

This approach has also been attempted by Koch et al. (2005), who used FTTCR-MS (positive ion mode) to analyze samples that were isolated by Ci8 SPE from the Weddell Sea in Antarctica. For six samples from depths of 30-4600 m, an average of 1064 245 molecular formulae could be assigned for each sample by assuming that the compounds contained only C, H, and O. Those molecular formulae were used, in turn, to calculate an intensity-weighted average elemental composition for each sample. If the tabulated average elemental compositions and atomic ratios of Koch et al. (2005) for the six samples of marine DOM are themselves averaged, the... 

Worker exposure to alkanes, especially the lower-molecular-mass compounds, is most likely to come from inhalation. In an effort to set reasonable values for the exposure by inhalation of vapors of solvents, hydrocarbons, and other volatile organic liquids, the American Conference of Governmental Industrial Hygienists sets threshold limit values (TLVs) for airborne toxicants.1 2 The time-weighted average exposure (E) is calculated by the formula... 

The weight-average molecular weight follows from the formula... 

Poloxamer 331 occurs as a practically colorless liquid. It is a block copolymer condensate of ethylene oxide and propylene oxide with an average formula weight of 3800, a specific gravity of about 1.02, and a refractive index of about 1.452. It is very slightly soluble in water at 25°, but is freely soluble at 0° it is freely soluble in alcohol, but is insoluble in propylene glycol and in ethylene glycol. 

The definition of net cash flow (NCF) for capital budgeting purposes is after tax cash flows from operations discounted at the present value of the cost of capital.26 In net present value analysis the cost of capital is a pre determined value based on the opportunity cost of capital. The cost of capital is defined as a weighted average cost of capital (WACC) and takes into account the firm s capital structure, the cost of equity and debt capital, and tax rates. The formula for the weighted average cost of capital (WACC) is... 

Organic complex acids Typical color Average formula Average molecular weight... 

If we have sufficiently sampled the possible arrangements of molecules in the simulation and have an accurate method to calculate their energy E, then the above formula will give a Boltzmann weighted average of the property X... 

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