White powder unknown

Martin Heinrich Klaproth (1743-1817). William Gregor (1761-1817), a minister who also dabbled in experiments, discovered a type of sand in 1791 from which a mysterious white powder could be produced. Klaproth recognized the yet-unknown element, and Henri Moissan (1852-1907) prepared pure titanium by electrolysis. 

You need to take samples of (a) water suspected of pollution by organic compounds, (b) an unknown white powder and (c) diesel fuel containing anti-theft marker dyes. In each case, decide which of the containers in the following list would be suitable. You can use the same container for more than one application. Containers (i) polyethylene bag with freezer-tie closure, (ii) can with screw top, (iii) glass bottle and (iv) polypropylene bottle. 

The Hanawalt method is relatively straightforward for unknowns which are nearly single phase. For multiphase mixtures the identification becomes tedious. Consider the data for a white powder given in Table 4 (7). Again the search is begun with the two most intense lines, 2.41 A and 3.04 A, but no match is found for this line-pair. Now a new line-pair must be chosen and the first and third most intense lines seem likely. Searching the Hanawalt manual with the pair 2.41 A and 1.70 A yields the possibilities 7-TaH, CaO, and NaYOa. Only the four lines of the CaO standard pattern lines match the lines in the unknown pattern. 

Urine Bile 1 Other analyze unknown white powder... 

O Imagine that you are an analytical chemist. You are presented with an unknown compound, in the form of a white powder, for analysis. Your job is to determine the molecular formula of the compound. Create a flow chart that outlines the questions that you would ask and the analyses you would carry out. Briefly explain why each question or analysis is needed. 

The test may be to identify an unknown white powder, e.g. is it sugar or heroin The test may be to determine the amount of Ag per cm of photographic paper. 

PROP White powder turning yellow when heated. Moisture sensitive. Mp 675° (decomp 460°), bp decomp, d 2.805. Decomp on heating with loss of O2. Undergoes transition from hexagonal room temp phase to a phase of unknown symmetry at 5°. 

Consider the data in Table 2-3. Students were asked to find the density of an unknown white powder. Each student measured the volume and mass of three separate samples. They reported calculated densities for each trial and an average of the three calculations. The powder was sucrose, also called table sugar, which has a density of 1.59 g/cm. Who collected the most accurate data Student A s measurements are the most accurate because they are closest to the accepted value of 1.59 g/cm. Which student collected the most precise data Student C s measurements are the most precise because they are the closest to one another. 

Busulfan is a white powder that is soluble in acetone. The powder is insoluble in water and readily hydrolyzes in water. Any environmental hazards that pose threats to the environment remain unknown. Busulfan is a pharmaceutical and is used in relatively small amounts therefore, so far it has been of little regulatory concern to the US Environmental Protection Agency. The potential threat of busulfan exposure is limited to workers involved in its manufacture, to patients receiving this agent as a chemotherapeutic regime, and to hospital personnel administering the drug to patients. 

PHYSICAL PROPERTIES white powder, leaflets, or large color-less crystals characteristic odor soluble in water, alcohol, benzene, ether, and hot petroleum ether slightly soluble in ligToin MP (58°C, 136°F) BP (2l l°C, 4l2°F) DN (unknown) SG (unknown) VD (3.2) VP (0.8 mmHg at 77°F). 

PHYSICAL PROPERTIES fine white to yellow-white powder darkens and develops a clay-like odor when moistened earth taste possesses high lubricity (i.e., slipperiness) insoluble in water not soluble in dilute acids, alcohol, ether, and alkali hydroxides MP (unknown) BP (NA) DN (1.8-2.6 g/cm ) SG (1.8-2.6) VD (NA) VP (0 mmHg approximately) pH (4.5-6.5 (slurries)). 

PHYSICAL PROPERTIES colorless crystals or white powder chlorine-like odor very sparingly soluble in water sparingly soluble in organic solvents, including acetone, 2-propanol, and dichloromethane MP (218-219°C, 424-426°F) BP (decomposes) DN (unknown) SG (unknown) VD (NA) VP (6.16 x 10 mmHg at 95°F). 

PHYSICAL PROPERTIES fluffy colorless to white powder odorless, hygroscopic solid sometimes dyed black exists as a liquid above 95°F (35°C) good solubility in water sparingly soluble in methanol and ethanol practically insoluble in acetone and carbon tetrachloride MP (200°C, 392 F) BP (decomposes below melting point at 200 C) DN (unknown, but >l) SG (>l) VD (NA) VP (approximately 0 mmHg at 20 C). 

A solution of 20 g. of NaN03 in 25 ml. of water is prepared, mixed with 42 ml, of phosphoric acid (d 1.3) and evaporated on a water bath. The residue is then heated for four hours at 330°C and the melt is extracted with water. The salt is obtained as a practically insoluble white powder. The yield is about 95%. For unknown reasons, the preparation sometimes proves unsuccessful. 

The sharpness of Raman spectra also makes library searching very reliable, as seen in Figure 4.72a and b. The spectrum of an unknown white powder collected through an evidence bag, as in Figure 4.69, is compared to spectra of a variety of drugs. The match to methamphetamine is significantly better than the other possibilities (83 vs. 62-65 for the other compounds). 

Spectroscopy is the study of the interactions of electromagnetic radiation, or light, with matter in order to gain information about the atoms or bonds present within the system. There are many different types of spectroscopic techniques however, most of the techniques are based on the absorption or emission of photons from the material being studied. The applications of spectroscopy span a variety of disciplines and can allow scientists to, among countless other things, determine the elemental composition of a nearby dwarf star, the chemical identity of an unknown white powder sample, whether a transfected gene has been expressed, or the types of individual bonds within a molecule. 

Riffault et al. (1874) describe a while anlimoniale of lead , the preparation being to mix one part antimony sulfide (stibnite,. v.) with five parts potassium nitrate, this being heated to red hot the product is dissolved in water and a neutral lead acetate solution added. Essentially the same recipe occurs in the text by Bersch (1901), who describes this and lead antimonite as heavy, white powder... dearer than while lead [. v.], to which [it] is inferior in covering power, and which [it does] not exceed in permanence . The precise chemical composition seems to be currently unknown. See also lead antimonite. 

A linear chain polymer has no taste or odor, is a white powder, the specilic gravity is 1.12, is soluble among a wide variety of solutions, and has the unique characteristic of dissolving in aliphatic hydrocarbons that are low in price and have little odor. Unknown... 

Unknown 8.9 is the spectrum from a trace of white powder found in the pocket of a suspected smuggler. Is the mass spectrum consistent with that which you would expect from 2j3-methoxycarbonyl-3/ -benzoyloxytropane, or cocaine (Figure 8.7) ... 

UVA QUERCEVA — A Substance of much importance, yet unknown to the ancients. It is a certain concretion, in the form of a bunch of grapes, which forms in spring under the earth at the roots of oak-trees, originating perchance from a superfluous moisture of the roots. It has a stiptic taste, is outwardly of purple colour, but is white inwardly, and, as it were, milky. In the winter it becomes wood it should be collected in spring, dried in the shade, and then pulverised. The powder is most efficacious in dysentery the most desperate cases have I cured with one of these Uva. 

Properties White, amorphous powder of unknown constitution containing active oxygen. Evolves oxygen gas when dissolved in water hygroscopic. 

Bismuth pentafluoride under normal conditions is a white solid, which is probably polymerized by fluorine bridges. X-ray powder photography shows it to have the same structure as the body-centered tetragonal a-UF6 (49). Other halides of bismuth (V) are unknown. 

PHYSICAL PROPERTIES white crystalline or gray powder odorless bitter taste slightly soluble in water soluble in acetone and triethylene glycol fairly soluble in hot alcohol MP (198 C, 388 F) BP (de-composes) DN (> 1 g/cm3) SG (unknown) VP (low). 

PHYSICAL PROPERTIES white or slightly cream colored powder free-flowing material prepared commercially from lime and diatomaceous earth insoluble in water forms a silicon gel with mineral acids remains a free-flowing powder even when it absorbs 1 to 2.5 times its weight of liquids total absorption power for water about 600%, for mineral oil about 500% available surface area 95-175 mVg ultimate particle size 0.02-0.07 microns MP (1,540 C, 2,804°F) BP (unknown) DN (2.10 g/cm at 25 C) BULK DN (15-16 Ib/ft ) SG (2.9 at 20 C) VD (NA) VP (approximately 0 mmHg at 20 C). 

PHYSICAL PROPERTIES white to grayish white, very fine crystalline powder odorless insoluble in water, cold acids or in alkalies luster pearly or greasy adheres readily to the skin may be harder when impure MP (900-1000°C, 1652-1832°F) BP (unknown) DN (2.7-2.S g/cm ) SG (2.70-2.80) VP (0 mmHg approximately) MOHS HARDNESS (1-1.5). 

---