Solutions labeling

In a solution labeled 0.10 M H2S04, which of the following best describes the composition of the solution ... 

The solutes labeled in the chromatogram are as follows Peak Number Solute... 

The 0.001M CuCl2 solution labelled by 64Cu and K2Cr207 solution (pH 2) labelled by 51Cr were used to find out the best technology of... 

Repeat step 2 again, but use a larger graduated cylinder (25 or 50 mL) to measure the 10 mL of stock solution. Label as 4/1, 4/2, etc., to indicate that they are solutions 1 to 5 prepared in step 4. 

Vortex vial intermittently for not less than 20 minutes. Water should come in contact with all internal surfaces, including the stopper during reconstitution. Reconstituted stock can be stored for 14 days at 2 to 8°C. Never freeze stock solution. Label stock with initials and date prepared. Vortex refrigerated reconstituted stocks 5 minutes before use. 

The term parameters of the lowest two allowed transitions of ethene calculated with different methods and different choices of computational parameters (48,51,98,105) are summarized in Table I. Included in the table are results obtained with four different basis sets. In combination with these basis sets the MCD parameters were obtained in the transition-based approach through solution of Eq. (60) by direct numerical solution (labeled Direct in Table I) and by expansion in a set of transition densities according to Eq. (72) (labeled SOS ). In some cases approximate forms of the A(1) and B(1) matrices were used (labeled Approx, see Eq. (64) and the discussion following it). MCD parameters derived from a fit to a spectrum obtained by calculation of the imaginary part of the Verdet constant are labeled as Im[V]. The parameters obtained from a fit to the spectrum obtained from the approximate form of Im[V] (see Section... 

The number of antibody binding sites on the wall is relatively small compared to the number of molecules in solution. Labelled and non-labelled molecules will react with the antibodies in proportion to their relative concentrations (Fig. 17.6). 

An aqueous solution labeled as 35.0% HCIO4 had a density of 1.251 g/mL. Calculate molarity and molality of the solution. 

Mercea, I. Simple analysis for some aqueous solutions labeled with deuterium. 

Are reagents and solutions labeled correctly with expiration dates ... 

Thus for a solute, labelled A, in a solvent, labelled B, the molality, mA is given by ... 

Figure 26. Schematic of the post hybridization detection method. A DNA target solution labeled with biotin is first incubated with the DNA probe functionalized chip. Targets diffuse passively from the solution to the surface where they hybridized with the probes if complementary. A solution containing streptavidin-functionalized magnetic labels is then incubated with the chip. Labels bind through the biotin-streptavidin interaction to where hybridization occurred. DNA hybridization is detected with spintronic transducers.

Determine the Strength of the Solution. With a pipette measure 10 cc. of the preparation into a 300-cc. Erlenmeyer flask, add 100 cc. of distilled water, and titrate against standard HC1 using phenolphthalein as the indicator. (See Experiment 6, page 75.) Carry out a duplicate titration with a second 10-cc. sample, and take the average of the results to give the normality of the solution. Label the bottle with the number of cubic centimeters of the solution, with its normality, and with the actual amount in grams of the hydroxide. 

Prepare a tube containing 10 mL of distilled water and 2 drops of concentrated NH3 solution. Label the tube NH3 and record the pH. Transfer two or three of the rinsed beads to this tube and observe for several minutes. Record your observations. 

An HC1 solution (labeled 0.200 N) is standardized using K1G3. Exactly 1.00 millimole of the latter is dissolved in water, spatula-fulls of KI and Na O ... 

O Suppose that you have four unknown solutions, labelled A, B, C, and D. You use a conductivity apparatus to test their conductivity, and obtain the results shown below. Use these results to answer the questions that follow. 

C-toluene standard—In a fume hood, mix sufficient 14C-toluene and unlabeled toluene to yield a known quantity of 14C-toluene (e.g., 1 to 2 nCi of 14C-toluene) per 0.1 ml of toluene solution. Label the sample with the 14C-toluene/ml with known disintegrations per minute (dpm). Y)u will need 250 ml of this solution. Save 50 ml of this reagent for the quenched 14C unknown. Dispense the other 200 ml to the students. 

Antipyrine-H2S04 reagent—Carefully add 1.25 liters of concentrated H2S04 to 1.25 liters of distilled water and allow to cool. Dissolve 12.5 g of antipyrine in the H2S04 solution. Label with warning strong acid. 

The necessity of immobilisation for many of the above-mentioned technologies can significantly limit their application. Recently free-solution, label-free molecular interactions were investigated with back-scattering interferometry (BSI) in an optical train composed of a helium-neon laser, a microfluidic channel and a position sensor.56 Molecular binding interactions between proteins, ions and protein as well as small molecules and protein could be monitored without labelling or immobilising any of the interaction partners. 

Figure 5. Planar bi layer setup. The system consists of two aqueous solutions, labeled cis and trans, separated by a planar bilayer. External voltage commands are applied to the cis side, with the trans side maintained at ground (defined as zero voltage). OSC—oscilloscope VCR—recording tape system.

The diazonium salt should be available at the beginning of the experiment. Remove a small quantity from the refrigerator and warm it rapidly to room temperature. Prepare approximately 10 M solutions by placing an accurately weighed 15- to 20-mg sample of the salt into each of three 100-mL volumetric flasks, and then make up to the mark with a 0.2 A/ HCl solution. Label the flasks and be sure to record the exact weight of salt placed in each flask. Return the unused diazonium salt to the refrigerator at once. Be careM not to waste it. 

Place 10 ml of urine in each of two 20-ml glass bottles fitted with plastic s ew-caps (McCartney bottles), and to one bottle add 1 to 2ml of M sulphuric acid and to the other add sufficient sodium bicarbonate to saturate the solution. Label the bottles A and B (acids and bases) respectively. Fill each bottle with a mixture of chloroform and isopropyl alcohol (9 1), screw on the caps, shake for 5 minutes, and centiifiige for 5 to 10 minutes. Aspirate the top aqueous phase using a Pasteur pipette connected to a water-operated vacuum pump, filter the chloroform extracts throu phase-separating paper to remove residual water, and collect the filtrates in 10-ml conical test-tubes ... 

Calcium chloride solutions (pH =6.2) labeled with Ca or 36ci were displaced vertically downward through columns of homogeneous, repacked, water-saturated sandy soil by a chemically identical solution labeled with Cl or Ca, respectively. Constant water fluxes, and solution activities of 1 to 15 pCi/dm, were used. Calcium solutions were analyzed by titration with disodium dihydrogen ethylenediamine tetraacetate to a murexide end point (11). The activity of radioactively labeled solutions was obtained by liquid scintillation techniques. Concentrations of adsorbed calcium were calculated from isotope dilution. The concentration of calcium chloride in the influent solution was 0.08 N. Because exchange of calcium for itself was the only chemical process affecting transport, the calcium chloride concentration remained constant at 0.08 N throughout each experiment, both within the column and in the effluent. 

Note that the description of a solution s composition may not accurately reflect the true chemical nature of the solution. Solution concentration is always given in terms of the form of the solute before it dissolves. For example, consider 1.0 liter of a solution labeled as 1.0 M NaCl. This solution was prepared by dissolving 1.0 mole of solid NaCl in enough water to make 1.0 liter of solution. The label 1.0 M does not mean that the solution contains 1.0 mole of NaCl units. Actually, the solution contains 1.0 mole of Na+ ions and 1.0 mole of CP ions. 

For solutes the standard state and the activity usually must be defined in terms of behavior under conditions of infinite dilution, where by definition the activity of a solute is set equal to its concentration. Thus at infinite dilution the ratio of activity to concentration (in whatever units) is unity, and y, = 1. When the value of some physical property of a solution is plotted as a function of concentration, a curve like those in Figure 2-2 is obtained. If the asymptote passing through the origin on the concentration scale is extrapolated to higher concentrations, we obtain the standard state of unit activity for the property in question. This hypothetical solution, labeled S, of unit concentration exhibits the same type of behavior as the infinitely dilute solution. The extent to which the real value of the physical property measured differs from the hypothetical value at a specific concentration is expressed by the activity coefficient, a coefficient that is simply the ratio between two measurable quantities. In Figure 2-2 the activity coefficient yj is the ratio BC/AC and is defined by... 

Label two 250 mL beakers 0.0200 M KMn04 and FeS04 solution. Label three of the flasks... 

One way of giving the exact concentration is to state the percentage of the volume of the solution that is made up of solute. Labels on fruit drinks show their concentration like the one in Figure 13. When a fruit drink contains 15 percent fruit juice, the remaining 85 percent of the drink is water and other substances such as sweeteners and flavorings. This drink is more concentrated than another brand that contains 10 percent fruit juice, but it s more dilute than pure juice, which is 100 percent juice. Another way to describe the concentration of a solution is to give the percentage of the total mass that is made up of solute. 

Obtain three 96-well microplates and four labeled micropipets containing the four solutions calcimn nitrate solution, strontimn nitrate solution, barium nitrate solution, and sodimn oxalate solution. Label the microplates calcium, strontium, and barium. 

Test the six solutions (the colorless ones) remaining from Step 5 with the solution labeled 0.3 M NaOH. To do this, add a few drops of this solution to each of the six test tubes and shake. All solutions will turn pink and a white precipitate (an insoluble solid) should form in one of the test tubes. This solid may appear as a cloudiness that is difficult to see. If you see no cloudiness in any of the test tubes, add a few more drops of the 0.3 M NaOH to all tubes and shake. Record which white solid produces the white cloudiness and how many drops of the NaOH were required. The white precipitate identifies this solid. Complete the flow chart (Figure 3.6) for Step 6. 

Note the color of the solution labeled Fe3+. This color is due to the presence of the Fe3+. Place one drop of this solution in a test tube, add one drop of 12 M HC1 and dilute to approximately 1 mL with water. Shake. Add 1 drop of 1 M KCNS and shake again. A blood-red color is the observation for a positive test for Fe3+. The reaction is... 

In three separate test tubes labeled Al3+, Ca2+, and Ba2+, place 1 mL of the solution labeled Al3+, 1 mL of the solution labeled Ca2+ and 1 mL of the solution labeled Ba2+. Add 2 drops of 6 M HN03 to each, shake, then add 1 mL (20 drops) of 6 M NH4OH to each and shake again. A gelatinous white precipitate forms in the test tube containing the Al3+ ion. This is the positive test for Al3+. No precipitate forms in the other tubes. The reaction is... 

Place two drops of the solution labeled NH4 on a watch glass. Add five drops of water and swirl to mix. Then add 2 drops of 4 M NaOH. Try to detect the odor of ammonia. If you cannot smell the ammonia, warm the watch glass gently on a hot plate and try again. 

Set up a hot water bath by half-filling a 250-mL beaker with distilled water and placing it on a hot plate so that the water becomes very hot before performing this test. Place five drops of the solution labeled P04 in a test tube and add two drops of concentrated HN03. Shake. Add five drops of ammonium molybdate solution, shake, and place in the hot water bath for 5 minutes. The formation of a yellow color or yellow precipitate is the positive test for phosphate. Bear in mind that contamination with residue from phosphate-containing soap may give a false-positive test for the unknowns. 

Place 1 mL of the solution labeled C03 in a test tube. While carefully watching as the drops contact the solution, add 2 drops of 1.5 M H2S04 and check for the formation of gas bubbles. Carbonate will form carbon dioxide gas when acidified and these bubbles will be clearly visible for a fraction of a second as the acid contacts the solution. The reaction is... 

Place 1 mL of the solution labeled S04 in a test tube and add 1 mL of 3 M HC1. Then add 10 drops of 0.2 M BaCl2. The formation of a white precipitate under these conditions is the positive test for sulfate. The reaction is... 

Place one drop of the solution labeled CP in a test tube. Add 20 drops of water, 2 drops of 3 M HN03 and shake. Now add 2 drops of 0.1 M AgN03. The white precipitate that forms is AgCl. The reaction is... 

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