141. Solving a chemistry problem
Determine the amount of heat required to heat 1 kg of cristabolite (B-SiO2) from 16 to 1538 C.
141. Solving a chemistry problem
A weighed portion of steel weighing 2,000 g was dissolved in nitric acid and, after appropriate treatment of vanadium, titrated potentiometrically...
141. Solving a chemistry problem
Cis-1,2-dichloroethylene in vinylidene chloride was determined by gas chromatography using toluene as an internal standard, and the following data...
141. Solving a chemistry problem
The flow rate of the non-sorbing argon carrier gas is 40 cm3 / min. Calculate the retention volume and the reduced retention volume of compound X on...
141. Solving a chemistry problem
Determine the length of the chromatographic column if for chloroform the height equivalent to the theoretical plate is 0.1 mm, retention time 212 s...
141. Solving a chemistry problem
Write the formula for a micelle of a silver iodide sol obtained as a result of the reaction: AgNO3 KJ = AgJ ↓ KNO3 if AgNO3 is taken in a 4-fold...
141. Solving a chemistry problem
Find the ratio of the mean shear values of particles with radii r = 2.5 * 10 ^ -9 m and r = 5.5 * 10 ^ -7 m.
141. Solving a chemistry problem
In an isolated system, a chemical reaction occurs spontaneously with the formation of a certain amount of the final product. How does entropy change...
141. Solving a chemistry problem
A glass sample weighing 0.1000 g was dissolved in a mixture of H2So4 and HF, the solution was evaporated, the residue was moistened with HCl and...
141. Solving a chemistry problem
A portion of the test water with a volume of 25.0 ml was diluted with distilled water in a 500.0 ml volumetric flask and photometric in flame in the...
141. Solving a chemistry problem
From a sample of steel weighing 0.2000 g after appropriate treatment, 100.0 ml of a solution containing MnO4- and Cr2O72- was prepared, its optical...
141. Solving a chemistry problem
To prepare standard solutions of titanium (IV) and vanadium (V), a sample of steel free of vanadium and titanium was dissolved in nitric acid. In six...
141. Solving a chemistry problem
3. The content of samarium in cerium dioxide was determined by the addition method. A standard solution of samarium nitrate was prepared by...
141. Solving a chemistry problem
A weighed portion of nepheline syenite weighing m g was treated with a mixture of hydrofluoric and nitric acids and diluted to 100.0 ml. Solid...
141. Solving a chemistry problem
When determining lead in ethyl alcohol, the analyzed solution with a mass of m g was evaporated, the dry residue was dissolved in hydrochloric acid...
141. Solving a chemistry problem
14. For turbidimetric determination of chloride ion, 20.0 ml of KCI solution (T = 1.051 mg / ml) was placed in a 100.0 ml volumetric flask in a 100.0...
141. Solving a chemistry problem
To determine silver in the alloy by phototurbidimetric titration, a sample of the analyzed metal weighing 3.17 g was dissolved in acid and brought to...
141. Solving a chemistry problem
In a sample of an organic compound weighing m g, oxygen was quantitatively converted to CO2. The carbohydrate dioxide was dissolved in an...
141. Solving a chemistry problem
A sample of a copper alloy weighing 0.7500 g was dissolved, the volume of the solution was brought to 250.0 ml, and 20.00 ml of the prepared solution...
141. Solving a chemistry problem
18. A weighed portion of proline weighing 0.0480 g (M = 115.13 g / mol) of pure grade was dissolved in glacial acetic acid and titrated with 0.1 M (K...
141. Solving a chemistry problem
5. In 0.1 M KCI (pH7), D-riboflavin C17H20N4O6, thiamine C12H17N4OSCl.HCl and nicotinic acid C5H4NCOOH have half-wave potentials E1 / 2...
141. Solving a chemistry problem
6.Polarography against the background of dimethylformamide of standard solutions of diallylaminoethyl methacrylate (DAMA) and diallylaminoethyl...
141. Solving a chemistry problem
7.To determine lead in zinc ore by the addition method, a sample of ore weighing m g was dissolved in a mixture of acids, iron (III) was reduced...
141. Solving a chemistry problem
5.A sample of a nonferrous alloy weighing m g was dissolved and by electrolysis at a constant current intensity I during time t, copper was...
141. Solving a chemistry problem
The amount (V) of CO (273 K and 1.01 * 10 ^ 5 Pa) adsorbed by 1 g of coal at 273 K and various pressures is as follows: P * 10–3, Pa 9.8 24.2 41.3...