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SMIRNOVA et al.
operation procedure have been described in [18].
Temperature was measured by means of iron–rhodium
resistance thermometer calibrated in correspondence
with MTSh-90. As cold carriers were used liquid
helium (for the temperature 5–6 K and higher) and
nitrogen (for 80 K and higher). For testing the
measuring procedure we measured heat capacity of
benzoic acid of K-1 sort [19]. The result obtained
coincided with the heat capacity value of reference
benzoic acid within ±2% in the region of 6–15 K,
±0.5% between 15 and 40 K and ±0.2% in the range of
40–350 K. Error at the measuring of phase transitions
temperature was ±01 0. K, of phase transition enthalpy
±0.2%.
Molecular weight of the studied object was calculated
using IUPAC Table of Atomic Weights [21].
Combustion energy of I was measured in the
modernized calorimeter B-08-MA with isothermal
cover and static bomb [22]. Oxygen pressure in the
bomb was 25×105 Pa. The calorimeter energetic factor
W = 14805.1±2.5 J Ω–1 was measured at combusting
reference benzoic acid of K-2 sort. Testing of
reliability by combustion of reference succinic acid
showed that its combustion energy actually
corresponds to property data sheet within error
±0.017%.
The studied sample was combusted in a thin-walled
quartz crucible being mixed with melted paraffin, the
combustion energy of the latter measured in
preliminary experiments was ΔUс = –46744±8 J g–1.
Application of paraffin as auxiliary substance provided
both necessary increase of temperature in the
experiment and conditions for complete oxidation of
the studied substances.
Measuring the heat capacity, temperature and phase
transition enthalpy in the region 330 K to 450 K was
carried out with automatic differential scanning
calorimeter operating on the pricnciple of triple heat
bridge (ADKTTM) [20]. The calorimeter construction
and measuring procedure are described in [20]. The
calorimeter operating reliability was tested by
measuring the heat capacity of a sample of synthetic
corundum and thermodynamic characteristics of
indium, tin and lead melting. The maximal error at the
heat capacity measuring is evaluated as ±2%, of
transition temperature ±0.5 K. Since the experiment of
the heat capacity measuring in the temperature range
from 330 K to 350 K was carried out with adiabatic
vacuum calorimeter with error ±0.2% and conditions
of measuring with dynamic scanning calorimeter were
optimized for coincidence of results on Cp0 on both
calorimeters in the same temperature range, we suggest
that at Т > 350 K the error at measuring Cp0 value is
±(0.5–2.0)%.
The Cp0 heat capacity measuring was carried out in
the temperature range from 6 K to 450 K. The sample
weight of the samples loaded to ampoules for BKT-3
and ADKTTM were, respectively, 0.7555 g and
0.7499 g. With BKT-3 were obtained 110 experi-
mental values of heat capacity in two series, with
ADKTTM 78 values in one series (Table 1). The
substance heat capacity was 20–70% of the total heat
capacity of the ampoule with the substance in the
range from 6 K to 115 K and 25–35 % in the range
from 115 K to 450 K. The experimental Cp0 values
were averaged using exponential and semi-logarithmic
polynomials. The mean square deviation of
experimental heat capacity values from averaging
curve Cp0 = f(T) was ±0.1% in the region of 19–80 K,
±0.18% for 75–210 K and ±0.15% for 210–360 K.
ACKNOWLEDGMENTS
This work is carried out in the framework of
national project “Education” and innovation program
of Niznii Novgorod State University.
REFERENCES
1. Sharutin, V.V., Sharutina, O.K., Platonova, T.P., Paku-
sina, A.P., Gerasimenko, A.V., Gerasimenko, E.A.,
Bukvetskii, B.V., and Popov, D.Yu., Koord. Khim.,
2003, vol. 29, no. 1, p.1317.
2. Sharutin, V.V., Sharutina, O.K., Pakusina, A.P., Pla-
tonova, T.P., Zhidkov, V.V., Pushilin, M.A., and
Gerasimenko, A.V., Koord. Khim., 2003, vol. 29, no. 10,
p. 750.
3. Wieber, M., Fetzer-Kremling, I., Reith, H., and Bur-
schka, C., Z. Naturforsch B., 1987, vol. 42, p. 815.
4. Sharutin, V.V., Sharutina, O.K., Molokova, O.V., Et-
tenko, E.N., Krivolapov, D.B., Gubaidullin, A.T., and
Litvinov, I.A., Zh. Obshch. Khim., 2001, vol. 71, no. 8,
p. 1317.
5. Rabinovich, I.B., Nistratov, V.P., Tel’noi, V.I., and
Sheiman, M.S., Termodinamika metallorganicheskikh
soedinenii (Thermodynamics of Organometallic
Compounds), Nizhnii Novgorod: Lobachevskii Univ.,
1996.
6. Smirnova, N.N., Letyanina, I.A., Larina, V.N., Mar-
kin, A.V., Sharutin, V.V., and Senchurin, V.S., J. Chem.
Thermodyn., 2008. (in press)
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 79 No. 4 2009
Smirnova
