Standard Molar Enthalpies of Formation of Sodium Alkoxides

J. Chem. Thermodynamics 39 (2007) 449–454 www.elsevier.com/locate/jct

Standard molar enthalpies of formation of sodium alkoxides

K. Chandran a, T.G. Srinivasan a, A. Gopalan b, V. Ganesan a,*

a Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, TN, India b Industrial Chemistry Department, Alagappa University, Karaikudi 630 006, TN, India

Received 14 April 2006; received in revised form 9 July 2006; accepted 20 July 2006 Available online 12 August 2006

Abstract

The molar enthalpies of solution of sodium in methanol, ethanol, and n-propanol and of sodium alkoxides in their corresponding alcohols were measured at T = 298.15 K using an isoperibol solution calorimeter. From these results and other auxiliary data, the standard molar enthalpies of formation Df H mðRONa; crÞ of sodium methoxide, sodium ethoxide, and sodium n-propoxide were calculated and found to be {(366.21 ± 1.38), (413.39 ± 1.45), and (441.57 ± 1.18)} kJ Æ mol1, respectively. A linear correlation has been found between Df H mðRONaÞ and Df H mðROHÞ for R = n-alkyl, enabling the prediction of data for other sodium alkoxides. Ó 2006 Elsevier Ltd. All rights reserved.

Keywords: Sodium methoxide; Sodium ethoxide; Sodium n-propoxide; Solution calorimeter; Enthalpy of formation

1. Introduction viz. methanol [2], ethanol [3], Jaysol SS [4], propanol [5,6], butyl cellosolve [7], ethyl carbitol [8,9], etc., have been used Liquid sodium is used as coolant in fast reactors (FRs). world wide for sodium removal purposes. During the operation of these reactors, a thin layer of There were reports of run-away reactions leading to sodium adheres to the steel components in the coolant cir- accident when ethyl carbitol was used for cleaning sodium cuit due to wetting. During reactor maintenance, some of storage tanks in France [8] and Germany [9]. Measure- these components need to be replaced or maintained peri- ments of thermochemical data such as enthalpy of forma- odically. Exposure of such sodium wetted components to tion, enthalpy of solution, heat capacity, thermal air could lead to ﬁre and possible hydrogen explosion as decomposition behaviour, etc., of sodium alkoxides are the reaction between sodium and moisture present in air useful for better understanding of sodium–alcohol reaction is highly exothermic in nature. In addition to posing safety and to avoid recurring of such eventualities during sodium related problems, this reaction also adversely aﬀects the cleaning processes. The preparation and characterization mechanical properties of the steel components due to the of sodium alkoxides namely, sodium methoxide, sodium formation of sodium hydroxide. These problems could be ethoxide, and sodium n-propoxide were reported elsewhere tackled by using suitable solvent to dissolve sodium under [10]. Heat capacity measurements, crystal structure elucida- controlled conditions and avoiding residual sodium tion, thermal decomposition, and kinetic analysis of all hydroxide on the components. Lutton et al. [1] have these sodium alkoxides were studied and reported else- described several sodium removal techniques. The highly where [11–13]. Since data on enthalpy of solution of reactive sodium metal can be converted into its less reactive sodium alkoxides in alcohol and enthalpy of formation of compound either by using an aqueous or a non-aqueous sodium n-propoxide are not available, the present work reagent. Among the non-aqueous reagents, several alcohols was taken up. The enthalpy of formation of sodium methoxide, and sodium ethoxide was also measured in the pres- * Corresponding author. Tel.: +91 44 27480098; fax: +91 44 27480065. ent study, compared with the reported data [14–19] as E-mail address: [email protected] (V. Ganesan). given in table 1 and discussed.

2. Experimental calorimetric vessel was made up of a double walled, bright silvered, vacuum-sealed glass Dewar having a capacity of 2.1. Chemicals 400 cm3 and fitted with a perspex flange with an O-ring. The top flange has appropriate provisions to facilitate the Nuclear grade sodium (mass fraction purity 0.995) from introduction of stirrer, a sample bulb, a calibration heater Alkali Metals, India, was further purified by vacuum distil- and a thermistor probe. The calibration heater used was a lation. The HPLC grade methanol (mass fraction purity PTFE-coated KARMA wire with a resistance of 4.35 X, 0.998) from Ranbaxy Fine Chemicals, India, absolute eth- wound non-inductively over a PTFE disc and enclosed in anol (mass fraction purity 0.999) from Hayman, UK, and a glass bulb. The bulb was filled with n-hexadecane AR grade n-propanol (mass fraction purity 0.995) from (>0.99 mass fraction purity) from Kasci Kogyo, Tokyo, SD Fine Chemicals, India, were further purified by distilla- enough to submerge the heating element for better heat tion [20] and were used for the preparation of their respec- transfer. The sample tube had a thin walled bulb at the tive sodium alkoxides. base, provision for introducing a plunger, which could move up and down through a leak tight fitting. Using this 2.2. Preparation of sodium alkoxides plunger the thin walled base could be broken in order to introduce the sample in to the solvent. The calorimetric The reaction of sodium metal with alcohol to yield the vessel was kept in a constant temperature water bath hav- respective sodium alkoxide was performed in dry argon ing a control accuracy of ±0.01 K. The temperature of the atmosphere using a gas-tight glass vessel. Solid sodium bath was maintained at 298.15 K throughout the experi- pieces weighing about 500 mg each were added to 150 cm3 ment. A thermistor probe with a sensitivity of 2 Æ 104 K of alcohol taken in the reaction vessel. When the alcohol was used to measure the temperature in the calorimetric 1 was nearly saturated, the addition of sodium was stopped. vessel. A HP 34401A, 62 digit, multimeter was used for pre- The excess alcohol was removed by vacuum distillation cise current measurement. A control unit consisting of a and the reaction product was dried at room temperature stabilised power-supply unit, a constant-current power for about 6 h. The temperature of the reaction vessel was supply unit with a quartz crystal based timer and glitch free subsequently raised to 353 K to remove the final traces of solid-state relay was used for switching the supply ON and alcohol. A free flowing milky white powder of sodium alk- OFF for a preset time during the electrical calibration. oxide was obtained and stored in the argon atmosphere Both temperature and time data were acquired through a glove box. The formation and phase purity of sodium alkox- personal computer. The calorimeter performance was ides were confirmed by IR spectroscopy and X-ray powder tested using KCl from NIST (SRM 1655), which had been diffraction studies and the chemical assay was determined by heated at T = 800 K to remove occluded water, cooled and Atomic Emission Spectroscopy and CHNS analyser. stored in a dry argon atmosphere glove box. Since KCl is moisture sensitive, weighing and loading operations were 2.3. Calorimeter performed in an argon atmosphere dry box. Each addition of KCl was carried out with 100 cm3 of distilled water. The The schematic of an iso-peribol solution calorimeter calorimeter performance was also tested with tris (hydroxy used in the present work was reported elsewhere [21]. The methyl) amino-methane (Tris). The enthalpy of solution

TABLE 1 Thermochemical data on (sodium + alcohol) systems Serial No. Author Reaction scheme DsolH mðRONa=ROHÞ= Df H mðRONa; crÞ= ðkJ mol1Þ ðkJ mol1Þ 1 Forcrand and Berthelot [14] Na CH OH CH ONa 1=2H 200.96 þ 3 excess !½ 3 CH3OH þ 2 Na C H OH C H ONa 1=2H 187.02 þ 2 5 excess !½ 2 5 C2H5OH þ 2 Na n-C H OH C H ONa 1=2H 177.19 þ 3 7 exces !½ 3 7 C3H7OH þ 2 2 Blanchard et al. [15] 2C H ONa 0:1N H SO soln Na SO C H OH 490.8 ± 5.7 2 5 þ 2 4 !½ 2 4H2O þ½ 2 5 H2O 3 Voice [16] Na C H OH C H ONa 1=2H 189a þ 2 5 excess !½ 2 5 C2H5OH þ 2 4 Leal et al. [17] CH ONa H O NaOH CH OH 58.3 ± 2.4 372.4 ± 2.4 3 þ 2 excess !½ H2O þ½ 3 H2O C H ONa H O NaOH C H OH 60.9 ± 1.8 411.6 ± 1.9 2 5 þ 2 excess !½ H2O þ½ 2 5 H2O i-C H ONa H O NaOH C H OH 54.0 ± 1.5 461.6 ± 1.7 3 7 þ 2 excess !½ H2O þ½ 3 7 H2O CH ONa 0:1 N HCl soln NaCl CH OH 113.6 ± 3.0 375.7 ± 3.1 3 þ !½ H2O þ½ 3 H2O 5 This work Na CH OH CH ONa 1=2H 203.95 ± 1.30 366.21 ± 1.38 þ 3 excess !½ 3 CH3OH þ 2 Na C H OH C H ONa 1=2H 190.43 ± 1.34 413.39 ± 1.45 þ 2 5 excess !½ 2 5 C2H5OH þ 2 Na n-C H OH n-C H ONa 1=2H 180.87 ± 0.84 441.57 ± 1.18 þ 3 7 excess !½ 3 7 C3H7OH þ 2 CH ONa CH OH CH ONa 76.84 ± 0.34 3 þ 3 excess !½ 3 CH3OH C H ONa C H OH C H ONa 54.84 ± 0.39 2 5 þ 2 5 excess !½ 2 5 C2H5OH n-C H ONa C H OH n-C H ONa 41.90 ± 0.66 3 7 þ 3 7 excess !½ 3 7 C3H7OH a Value taken from figure since no raw data were available. K. Chandran et al. / J. Chem. Thermodynamics 39 (2007) 449–454 451 was measured by dissolving known amount of Tris (0.997 TABLE 2 mass fraction purity) from MERK, UK, in 100 cm3 of The molar enthalpies of solution of sodium in alcohols at T = 298.15 K 3 1 0.1 mol Æ dm HCl (aq). Sample m/g DH/J DsolH mðNa=ROHÞ=ðkJ mol Þ Na (cr) {methanol} 0.0137 121.27 203.50 2.4. Calorimeter measurement M = 22.9898 g Æ mol1 0.0106 94.9 205.82 0.0181 159.69 202.83 Metallic sodium samples (10 to 40) mg were taken in a 0.0509 450.89 203.65 Mean: 203.95 ± 1.30a dry sample holder glass bulb kept in high purity argon atmosphere glove box suitable for handling liquid alkali Na (cr) {ethanol} 0.0095 78.27 189.41 3 0.0398 331.7 191.60 metals [22]. Exactly 200 cm of the alcohol (methanol, eth- 0.0151 125.82 191.56 anol, and n-propanol) were transferred into the calorimetric 0.0310 255.04 189.14 vessel. Then it was fitted with the top flange and immersed Mean: 190.43 ± 1.34a in the constant temperature water bath and allowed to Na (cr) {n-propanol} 0.0093 72.88 180.16 attain thermal equilibrium. The temperature of the calorim- 0.0141 111.27 181.42 eter was recorded against time. When temperature of the 0.0207 163.66 181.76 0.0108 84.63 180.15 solvent reached a stable value, the calorimeter was cali- a brated by electrical heating by applying a constant current Mean: 180.87 ± 0.84 for a known time. The sodium sample was then introduced Note: m denotes the mass of sodium added, M the molar mass of sodium, DH the measured enthalpy change, and D H the molar enthalpy of in to alcohol by breaking the glass bulb. From the thermo- sol m solution. gram obtained, true temperature changes (DT) for known a Uncertainties are twice the standard deviation of the mean. energy input and sample addition were measured as detailed by Coops et al. [23] and were used for the evaluation of the TABLE 3 energy change for the reaction. The molar enthalpies of solution of sodium alkoxides in alcohols at Similar experiments were carried out by taking samples T = 298.15 K of dry sodium alkoxides in powder form (10 to 100) mg to Sample m/g DH/J DsolH mðRONa=ROHÞ= measure the enthalpy of solution. The quantity of alcohol ðkJ mol1Þ was measured before and after sample addition to check CH3ONa (cr) {methanol} 0.0219 31.22 77.02 1 for any evaporation loss of alcohol, which was found to M = 54.0244 g Æ mol 0.0281 39.99 76.88 be insignificant during all these experiments. 0.0315 44.52 76.35 0.0225 32.12 77.12 Mean: 76.84 ± 0.34a 3. Results and discussion C2H5ONa (cr) {ethanol} 0.0668 54.39 55.41 M = 68.0516 g Æ mol1 0.0605 48.76 54.85 The molar enthalpy of solution of KCl in distilled water 0.0596 47.64 54.40 DsolH m measured in this work to test the performance of 0.0636 51.01 54.58 the calorimeter is (17.23 ± 0.02) kJ Æ mol1 which is in close 0.0921 74.37 54.95 a agreement with the value of (17.21 ± 0.01) kJ Æ mol1 Mean: 54.84 ± 0.39 reported by Venugopal et al. [24] and NBS value of C3H7ONa (cr) {n-propanol} 0.0369 18.67 41.53 1 (17.241 ± 0.018) kJ Æ mol1 [25]. The value of the molar M = 82.078 g Æ mol 0.0461 24.03 42.78 enthalpy of solution of Tris measured in the present work 0.0353 18.07 42.02 0.0390 19.61 41.27 1 is DsolH m ¼ð30:13 0:23Þ kJ mol , which is in agree- Mean: 41.90 ± 0.66a ment with the NIST value of (29.77 ± 0.03) kJ Æ mol1 Note: m denotes the mass of sodium alkoxides added, M the molar mass of [26]. The results obtained in this study are listed in tables sodium alkoxides, DH the measured enthalpy change, and DsolH m the 2 and 3. molar enthalpy of solution. Table 1 gives the data available in the literature on a Uncertainties are twice the standard deviation of the mean. enthalpies of solution and enthalpies of formation of sodium alkoxides reported by various authors. These tion among the present values of enthalpies of solution values are compared with the present measured values. of sodium in alcohols and that reported by Forcrand The molar enthalpies of solution of sodium in various and Berthelot [14]. In the present measurements, the con- alcohols namely methanol, ethanol, and n-propanol mea- centration of RONa in alcohol is always very low (1 mol sured in the present study are given in table 2. The mean of Na/RONa to (4 to 20) Æ 103 moles of alcohol), assum- experimental values of DsolH mðNa=ROHÞ are {(203.95 ± ing this is effectively close to infinite dilution. The present 1.30), (190.43 ± 1.34), and (180.87 ± 0.84)} kJ Æ mol1, value for sodium-ethanol case is in good agreement with respectively, for the above cases. The values (200.96, the value reported by Voice [16] who made the measure- 187.02, and 177.19) kJ Æ mol1 are reported by Forc- ment with the dilution of 1:1000. rand and Berthelot [14]. Voice [16] has measured the Molar enthalpies of solution of sodium alkoxides molar enthalpy of solution in (sodium + ethanol) system namely sodium methoxide, sodium ethoxide, and sodium and the value is 189 kJ Æ mol1. There is a small varia- n-propoxide in corresponding alcohols measured in the 452 K. Chandran et al. / J. Chem. Thermodynamics 39 (2007) 449–454 present work are given in table 3. The mean of experimen- formation of sodium ethoxide reported by Blanchard [15] 1 tal values of DsolH mðRONa=ROHÞ are {(76.84 ± 0.34), is (490.8 ± 5.9) kJ Æ mol , which is distinctly high com- (54.84 ± 0.39), and (41.90 ± 0.66)} kJ Æ mol1, respec- pared with the values obtained in the present work and tively. The values from NBS Table for sodium methoxide, those reported in the literature [17–19]. The data on sodium and sodium ethoxide are (72.36 and 51.9) kJ Æ mol1, n-propoxide derived in the present work are reported for respectively [18]. The molar enthalpy of solution of sodium the first time. n-propoxide in n-propanol is reported for the first time. The derived enthalpies of reaction of sodium and alco- The reactions from which the standard molar enthalpies hols, namely methanol, ethanol, and n-propanol in the of formation of sodium alkoxides Df H mðRONa; crÞ have been present work are DrH mðNa=ROHÞ ¼ fð127:11 1:34Þ; derived in the present work are given in tables 4 and 5. ð135:59 1:40Þ; and ð138:97 1:07Þg kJ mol1, respec- Reaction (1) represents the formation of sodium alkoxide tively. The present values of enthalpies of reaction of and its subsequent dissolution in excess alcohol. Reaction sodium with methanol and ethanol are compared by sub- (2) represents the dissolution of crystalline sodium alkoxide tracting the values of enthalpies of formation of sodium in excess alcohol. The enthalpy changes for reactions (1) methoxide, sodium ethoxide and the corresponding alco- and (2) were measured experimentally in the present work. hols reported in NBS Table and found to be 129.1 and The enthalpy change for the reaction involving 1 mol of 136.1 kJ Æ mol1. The present measurements are in good sodium with 1 mol of alcohol ðDHð3Þ¼DrH mðNa=ROHÞÞ agreement with NBS data. was deduced from DH(2) and DH(1). The enthalpy of for- Leal et al. [17] have reported a linear expression for cor- mation of sodium alkoxide DHð5Þ¼Df H mðRONa; crÞ for var- relating the enthalpies of formation of sodium methoxide, ious alcohols obtained from DH(3) and DH(4) [27] are sodium ethoxide, and sodium n-butoxide against enthalpies given in table 5. of formation of their corresponding alcohols. A similar Enthalpies of formation of sodium methoxide, sodium procedure is followed in the present work for the com- ethoxide, and sodium n-propoxide derived in this work pounds of sodium alkoxides. The linear expression are Df H mðRONaÞ ¼ fð366:21 1:38Þ; ð413:39 1:45Þ; obtained is given below and is also shown in figure 1. and 441:57 1:18 kJ mol1, respectively. Leal et al. ð Þg DH ðRONa; crÞ¼ð1:19 0:02Þ DH ðROH; lÞ [17] have reported the enthalpy of formation of sodium f f methoxide derived by two different methods as given ð82:10 6:15Þ: ð1Þ in table 1 and the values are (372.4 ± 2.4) and Good linear correlation (r = 0.9998) is observed in equa- (375.7 ± 3.1) kJ Æ mol1. The value for sodium methoxide tion (1), which is in good agreement with the expression reported in NBS Table is 367.8 kJ Æ mol1. The present reported by Leal et al. [17]. Similar practices have also been derived data for sodium methoxide are in good agreement reported in the literature for many inorganic and organo- with the NBS value [18,19] although a small variation is metallic complexes of transition metals of type MXnLm observed with the data reported by Leal et al. [17]. The (M = Ti, Mo, W; X = halogen; L = H, alkyl, aryl, alkoxy, enthalpy of formation of sodium ethoxide derived in azobenzene, etc.) and used to estimate the enthalpies of for- this work is in good agreement with the value of mation of new complexes [28,29]. (411.6 ± 1.9) kJ Æ mol1 reported by Leal et al. [17] and In a similar fashion, enthalpies of solution of sodium NBS [18,19] value of 413.8 kJ Æ mol1. The enthalpy of and sodium alkoxides in their respective alcohols obtained

TABLE 4

Reaction scheme (T = 298.15 K) for the standard molar enthalpy of formation of RONa(cr) with typical value for CH3ONa(cr) Reaction DH/(kJ Æ mol1)

1Na(cr) + nROH(l) ! [RONa](n1)ROH + 1/2H2(g) DH(1) = 203.95 ± 1.30 2 RONa(cr) +(n 1)ROH(l) ! [RONa](n1)ROH DH(2) = 76.84 ± 0.34 3Na(cr) + ROH(l) ! RONa(cr) + 1/2H2(g) DH(3) = 127.11 ± 1.34 4C(cr) +2H2(g) + 1/2O2(g) ! ROH(l) DH(4) = 239.1 ± 0.3 5Na(cr) +C(cr) +2H2(g) + 1/2O2(g) ! RONa(cr) + 1/2H2(g) DH(5) = 366.21 ± 1.38 Df H mðRONa;crÞ¼DHð5Þ¼DHð3ÞþDHð4Þ where DH(3) = DH(1) DH(2) R = –CH3 group.

TABLE 5 Standard molar enthalpies of formation of sodium alkoxides DHð1Þ¼DsolH mðNa=ROHÞ= DHð2Þ¼DsolH mðRONa=ROHÞ= DHð4Þ¼Df H mðROHÞ= DH(5)=Df H mðRONa; crÞ= ðkJ mol1Þ ðkJ mol1Þ ðkJ mol1Þ [27] ðkJ mol1Þ

R = –CH3 203.95 ± 1.30 76.84 ± 0.34 239.1 ± 0.3 366.21 ± 1.38 R=–C2H5 190.43 ± 1.34 54.84 ± 0.39 277.8 ± 0.4 413.39 ± 1.45 R=n-C3H7 180.87 ± 0.84 41.90 ± 0.66 302.6 ± 0.5 441.57 ± 1.18 Df H mðRONa; crÞ ¼ DHð5Þ¼DHð3ÞþDHð4Þ where DH(3) = DH(1) DH(2). K. Chandran et al. / J. Chem. Thermodynamics 39 (2007) 449–454 453

The enthalpy of formation of sodium n-propoxide cal- -360 culated using linear ﬁt data of Leal et al.is (438.14 ± 7.7) kJ Æ mol1, which is in good agreement -380 with the data of (441.57 ± 1.18) kJ Æ mol1 derived from

-1 the present work. Similarly the enthalpy of formation of mol . -400 sodium n-butoxide calculated using the linear ﬁt data of the present study is found to be (471.59 ± 6.16) 1 -420 kJ Æ mol , which is in close agreement with the value of 463.9 ± 5.0 kJ Æ mol1 derived by Leal et al. (RONa, cr) / kJ (RONa, º f

H -440 Δ 4. Conclusions

-460 The standard molar enthalpies of solution of sodium and its alkoxides, namely sodium methoxide, sodium -480 ethoxide, and sodium n-propoxide are measured at T = -340 -320 -300 -280 -260 -240 -220 298.15 K. Using these values, the standard molar enthal-

ΔH º (ROH, l) / kJ . mol-1 pies of formation and reaction of sodium methoxide, f ethoxide, and n-propoxide are derived. The standard molar FIGURE 1. Plot of enthalpies of formation of sodium alkoxides against enthalpies of formation, reaction and solution of sodium enthalpies of formation of the corresponding alcohol: , Leal et al. work; n-propoxide are reported for the first time. h, values from NBS table; m, present work; ——, present work fitted data; and – – –, Leal et al. fitted data. Acknowledgements in this work are plotted against enthalpies of formation of The authors are grateful to Dr. G. Periaswami, Head, corresponding alcohols and are shown in figure 2. The lin- Materials Chemistry Division, Chemistry Group, IGCAR ear correlation obtained from figure 2 for the enthalpy val- for his constant encouragement throughout the course of ues are given in equations (3) and (5), respectively. These the study and useful suggestions during the preparation correlations may be used to estimate the enthalpy of solu- of this paper. tions of other n-alkyl derivatives of sodium alkoxides. References DH solðNa=ROHÞ¼ð0:362 0:01ÞDH f ðROH; lÞ ð290:70 2:68Þ; ð2Þ [1] J.M. Lutton, R.P. Colburn, F. Welch, Atom. Energy Rev. 18 (4) DH solðRONa=ROHÞ¼ð0:551 0:01ÞDH f ðROHÞ (1980) 815–892. ð208:60 3:47Þ: ð3Þ [2] W. Haubold, C.Ch. Smit, K.Ch. Stade, in: Status of Sodium Removal and Component Decontamination Technology in the SNR Pro- gramme, IAEA/IWGFR-Specialist Meeting on Sodium Removal and Decontamination, Richaland, WA, USA, 14–16 February, 1978, pp. 1–7. IWGFR-23. -170 -30 [3] W.E. Ruther, C.R.F. Smith, in: EBR-II Experience with Sodium Cleaning and Radioactivity Decontamination, IAEA/IWGFR-Spe- cialist Meeting on Sodium Removal and Decontamination, Richa- -40 land, WA, USA, 14–16 February, 1978, pp. 182–194. -180 [4] J.G. Asquith, O.P. Steele, F.H. Welch, in: Sodium Removal Tech- -1 -1 nology – The Alcohol Process, Proceedings of the International -50 mol mol . . Conference on Liquid Metal Technology in Energy Production, Champion, Pennsylvania, 3–6 May, 1976, pp. 548–553. [5] K.Ch. Stade, in: Operating Experience in Cleaning Sodium-Wetted -190 -60 Components at the KNK Nuclear Power Plant, IAEA/IWGFR- Specialist Meeting on Sodium Removal and Decontamination, (Na / ROH) kJ º sol (RONa / ROH) / kJ / kJ / ROH) (RONa Richaland, WA, USA, 14–16 February, 1978, pp. 17–29.

-70 º sol H H Δ [6] P. Menzenhauer, H.U. Borgstedt, H.H Stamm, Th. Dippel, S. Kunze, Δ -200 D. Hentschel, in: Experience with Cleaning of Sodium-Wetted -80 Components and Decontamination at Nuclear Research Centre, Karlsruhe, IAEA/IWGFR-Specialist Meeting on Sodium Removal and Decontamination, Richaland, WA, USA, 14–16 February, 1978, -210 -90 pp. 30–37. -320 -300 -280 -260 -240 -220 [7] Roberto Caponetti, J. Nucl. Technol. 70 (1985) 408–423. Δ º . -1 [8] P. Marmonier, J. Del Negro Cea, in: Information about the Accident Hf (ROH, l) / kJ mol Occurred Near RAPSODIE, IAEA/IWGFR-Technical Committee FIGURE 2. Plot of enthalpy of solution of Na/ROH and RONa/ROH Meeting on Sodium Removal and Disposal from LMFRs in Normal versus enthalpy of formation of the corresponding alcohols: , Na/ROH; Operation and in the Frame Work of Decommissioning, 3–7 h, RONa/ROH; and ——, ﬁtted data. November 1997, France. IWGFR-98. 454 K. Chandran et al. / J. Chem. Thermodynamics 39 (2007) 449–454

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