Uman NUH | today: 12/22/2024
| Author(s) |
Poberezhets I.I., , , Uman National University of Horticulture Poberezhets V.I., , , Uman National University of Horticulture Poberezhets I.I., , , Uman National University of Horticulture |
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| Category | The Agronomy | ||
| year | 2019 | issue | Issue number 94. Part 1 |
| pages | 111-118 | index UDK | 663.2/5:664.1 | DOI | 10.31395/2415-8240-2019-94-1-111-118 (Link) |
| Abstract | Researching of water-alcohol-sugar solutions were carried out using two parameters. The density and refractive index of light solutions were measured. Mass fractions of sucrose were determined according to the density (Сρ) and the refractive index (Сn). The mass fraction of sucrose (Сn) was measured by a refractometer with a scale of mass percent sucrose. The mass fraction of sucrose (Сρ) can be measured by the aerometer with the scale of mass percentages of sugar. In this research the density of the solutions was measured by a pycnometer and according to the the table of densities of the solutions of sucrose, the mass fraction of sucrose (Сρ) was determined. Solutions of ethyl alcohol and sucrose were prepared. The volume fraction of alcohol was determined by the areometric method. The mass fraction of sucrose was determined by a refractometric method, which directly determines the mass fraction of sucrose in solution. At the same time, the moisture of the crystalline substance does not make any accuracy in the results of measurements of the concentration of solutions. Then the same volumes of solutions were mixed and the volume fraction of alcohol and the mass concentration of sucrose decreased twice. Within the precision of the experiment, sucrose, granulated sugar and rafinated sugar solutions have the same physical parameters, which is due to the absence of the influence of crystalline moisture on the concentration of solutions and the low content of impurities of the order of 0.1%. The results of experiment have shown that the mass fraction of sucrose is approximately equal to the arithmetic mean (Сn) and (Сρ) The volume fraction of ethyl alcohol is calculated by the formula Cs=K(Сn - Сρ ), where K is the coefficient value of which depends linearly on the mass fraction of sucrose (C%) K = 1,436 + 0,0106C. The accuracy of the method is depends on the accuracy of refractometric and areometric measurements. The average accuracy of the mass fraction of sucrose is 0.1% and the average accuracy of the volume fraction of ethyl alcohol is 0.2% vol. The density and refractive index of solution of ethyl alcohol and sucrose equally decrease to the temperature rises. The difference of the indication (Сn) and (Сρ) should remain unchanged, and according to the formulas of the method of two parameters the volume fraction of ethyl alcohol should not depend significantly on temperature. The volume fraction of ethyl alcohol calculated by the method of two parameters was the same at 26oC, as at 20o C. The mass fraction of sucrose at 20°C calculated by the method of two parameters was 15.0%, and at 26°C it was 14.5%, indicating the significant temperature dependence. | ||
| Key words | refractometer, density, temperature, sucrose, ethyl alcohol, mass fraction | ||