Indian Journal of Chemical Technology

VOLUME 8

NUMBER 2

MARCH 2001

CONTENTS

Dissolution and inhibition of monel (400) alloy in aqueous formic and acetic acid solutions

  V B Singh, R N Singh & Archana Gupta

75

 

 

Fluorimetric determination of bromofarm via its photochemical reaction with diphenyl-amine in aqueous Triton X-100 medium

  Anjali Pal & Manas Bandyopadhyay

83

 

 

Pyridine-2-acetaldehyde salicyloylhydrazone as reagent for extractive and spectrophoto metric determination of cobalt (II) at trace level

  S S Patil & A D Sawant

88

 

 

Electrosynthesis and photoelectrochemical characterization of ZnInSe

  R K Pathak

92

 

 

Electrochemical studies with plastic bonded zinc electrode for alkaline secondary batteries

  R Shivkumar, S Umamaheswari, G. Paruthimal Kalaignan & T Vasudevan

95

 

 

Reversed - phase extraction chromatographic separation of zinc(II) with trioctylphosphine oxide

  M D Rokade & P M Dhadke

103

 

 

Conversion of alliin to allicin in garlic - A kinetic study

  Rashmi Mishra, S K Upadhyay & P N Maheshwari

107

 

 

Crystallization of silver nitrate from saturated silver nitrate solution in nitric acid

  Cengiz  Ozmetin, Mehmet Copur, M Muhtar Kocakerim & Sinan Yapici

112

 

 

Formation and characteristics of high resolution photographic plates

  M K Sharma

120

 

 

Kinetics and process parameter studies in the synthesis of 2-amino-1-butanol from methyl-DL- a -aminobutyrate

  Sudip Mukhopadhyay & Sampatraj B Chandalia

128

 

 

Basic dyes removal from wastewater by adsorption on rice husk carbon

        D K Singh & Bhavana Srivastava

133

 

 

Synthesis and characterization of monomeric and polymeric dyes

  Hari R Maradiya & Vithal S Patel

140

 

 

 

 

Note

 

 

 

Effect of heating rate on the char yield and pore structure of chars prepared from viscose rayon cloth

  K Kumar, R K Saxena & A K Sarkar

149

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 75-82

 

Dissolution and inhibition of Monel (400) alloy in aqueous formic

and acetic acid solutions

 

V B Singh, R N Singh & Archana Gupta

Department of Chemistry, Banaras Hindu University, Varanasi 221005, India

Received 30 June 2000; accepted 17 November 2000

The corrosion behaviour of Monel (400) in different concentrations of formic and acetic acid solutions has been studied by potentiostatic technique, at different temperatures (30, 37 and 44°C). The maximum corrosion is observed in aqueous 20 mol/O formic and acetic acid solution. It was found that the extent of corrosion of the alloy is a function of acid concentration. The anodic polarisation curves show active corrosion behaviour of the alloy over the whole range of potential at each concentration of both the acids, individually. The cathodic polarisation curves are almost identical irrespective of the concentration of either acid. The inhibitive effect of some organotin compounds viz. Bu2SnCl2, PhSnCl3, Ph2SnCl2 and Ph3SnCl on the corrosion of monel (400) has been studied in aqueous solution mixture (20 mol/O) of either acid. The results have been discussed in the light of molecular structures of the organotin compound and their adsorption on the surface of the corroding metal. Among the inhibitors used Ph3SnCl functions as a better inhibitor in both the acids. SEM studies also show that the inhibitors act as passivator type inhibitor in acetic acid.

 

Indian Journal of Chemical Technology

Vol. 8, March 2001 pp.83-87

 

 

Fluorimetric determination of bromoform via its photochemical reaction with diphenylamine in aqueous Triton X-100 medium

Anjali Pal & Manas Bandyopadhyay

Civil Engineering Department, Indian Institute of Technology, Kharagpur 721302, India

Received 1 May 2000; accepted 2 November 2000

A new fluorimetric method based on the photochemical reaction of CHBr3 with diphenylamine (DPA) in aqueous Triton X-100 (TX-100) medium is described for the determination of bromoform (CHBr3). The fluorescence intensity of the product at 480nm (lex: 400nm) is a direct measure of CHBr3 concentration. The calibration graph is linear in the range of 0-21.8 ppm of CHBr3. The limit of detection (LOD) is 0.1 ppm of CHBr3. The effect of reagent concentration, TX-100 concentration, time of irradiation, interfering substances, and statistical parameters are discussed.

Indian Journal of Chemical Technology

Vol. 8, March 2001 pp.88-91

 

Pyridine-2-acetaldehyde salicyloylhydrazone as reagent for extractive and spectrophotometric determination of cobalt(II) at trace level

S S Patil & A D Sawant *

Inorganic Chemistry Division, The Institute of Science,15, Madam Cama Road, Mumbai 400 032, India.

Received 10 September 1999; accepted 22 November 2000

An extractive spectrophotometric method is described for the determination of cobalt(II) using pyridine-2-acetaldehyde salicyloylhydrazone (PASH) as reagent. For the extraction of cobalt(II) various experimental parameters such as acidity, reagent concentration, equilibration time are systematically studied to establish optimum conditions for quantitative extraction. Cobalt(II) is extracted quantitatively in the pH range 1.0 - 4.0. The yellow coloured 1:2 metal:ligand complex in chloroform is determined spectrophotometrically at 415 nm. Beer’s law was obeyed over the concentration range of 0.5-7.0 mg mL-1 of cobalt(II). The molar absorptivity and Sandell sensitivity were found to be 1.04 × 104 L mol-1 cm-1 and 5.63 ng cm-2 respectively. The method is precise and simple. It was applied for the analysis of high speed steels and pharmaceutical samples for the estimation of cobalt(II).

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 92-94

 

Electrosynthesis and photoelectrochemical characterization of ZnInSe

R K Pathak

Department of Chemistry, Govt PG College, Rajgarh 465 661, India

Received 7 June 1999; accepted 28 November 2000

Electrosynthesis of In doped ZnSe polycrystalline films by electrochemical co-deposition has been carried out to investigate the effect of In inclusion on photoelectrochemical characteristics of ZnSe. Photoactivity, capacitance and photoaction spectral studies have been used for characterization of the electrodeposits.A significant improvement in the quality of photoelectrodes was observed in In content of the preparation.

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 95-102

 

 

Electrochemical studies with plastic bonded zinc electrode for alkaline
secondary batteries

R Shivkumar, S Umamaheswari, G Paruthimal Kalaignan* & T Vasudevan

Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003, India

Received 1 June 1999; accepted 24 April 2000

The effects of small addition of CdO, Ca(OH)2 and Zn dust to the plastic bonded zinc electrode have been evaluated through triangular potential sweep voltammetry, potentiodynamic polarization (with temperature effect), impedance measurements, solution analysis and Porosity measurements. In the case of CdO additive, a composition of 2 % is preferred because of its enhanced ageing behaviour, good high temperature performance and minimum shape change despite its increased standby corrosion. 1 % Ca(OH)2 gives both good ageing behaviour as well as minimum idle corrosion. The additive Zn dust is not recommended owing to its poor ageing behaviour. Based on the above results, the suitable zinc electrode composition is suggested.

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 103-106

 

 

Reversed-phase extraction chromatographic separation of zinc(II) with trioctylphosphine oxide

M D Rokade & P M Dhadke*

Inorganic Chemistry Laboratory, Department of Chemical Technology,
University of Bombay, Matunga, Mumbai 400 019, India

Received 31 May 1999; accepted 1 February 2001

A new method for extraction chromatographic separation of zinc (II) was developed with Trioctylphosphine oxide as the stationary phase and nitric acid as mobile phase on silica gel as stationary support. Zinc was extracted from 2.5 M hydrochloric acid and then stripped with 4 M nitric acid and determined spectrophotometrically at 460 nm by murexide method. Zinc was separated from alkali, alkaline earths, chromium, iron, cobalt, nickel, cadmium, mercury, lead, trivalent rare earths, platinum group metals from binary mixtures by selective extraction of zinc. Zinc is also separated from multicomponent mixtures. The method was extended for the analysis of zinc in alloys and industrial sample.

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 107-111

 

 

Conversion of alliin to allicin in garlic –A kinetic study

Rashmi Mishraa , S K Upadhyay*a  & P N Maheshwarib

aDepartment of Chemistry,

bDepartment of Biochemical Engineering & Food Technology, H B Technological Institute, Kanpur 208 002, India

Received 14 May 1999; accepted 18 September 2000

A method for estimation of rate of conversion of alliin to allicin based on quantitation of pyruvic acid has been developed using sodium pyruvate and the kinetics of conversion of alliin to allicin have been studied. The effect of acetic acid (5-30% strength), ethanol (5-30% strength), buffers (pH 4.0-6.0) and temperature (30-50°C) on the rate of conversion of alliin to allicin is reported which elucidate that the rate of conversion decreases by increasing concentration of acetic acid or ethanol (rectified spirit) and increases with an increase in pH towards neutrality, the optimum temperature for this conversion being about 35°C.

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 112-119

 

 

Crystallization of silver nitrate from saturated silver nitrate solution in nitric acid

Cengiz Özmetin, Mehmet Çopur, M Muhtar Kocakerim & Sinan Yapici

Atatürk University, Chemical Engineering Department, 25240, Erzurum, Turkey

Received 20 October 1999; accepted 18 December 2000

The aim of the present work is to submit an investigation on the optimum conditions of crystallization of silver nitrate salt from saturated silver nitrate solution in nitric acid. The saturated solutions of AgNO3 at 70°C obtained by evaporation of dilute silver nitrate solutions with nitric acid were crystallyzied in a jacketed glass vessel with controlled cooling. The parameters for the crystallization operation were chosen as stirring speed and crystallization period. For each experiment, crystals obtained from operations were filtered, washed, dried, and their photographs were taken before particle size analysis. The differential and cumulative analysis and product yield calculations showed that the optimum values of the parameter for the crystallization of silver nitrate salt from saturated silver nitrate solutions with nitric acid were determined as 500 rpm stirring speed and 240 min crystallization period, with the highest yield.

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 120-127

 

Formation and characteristics of high resolution photographic plates

M K Sharma

Instruments Research and Development Establishment, Dehra Dun 248 008, India

Received 13 September 1999; accepted 30 November 2000

High resolution photographic plates having a coating of exceedingly fine-grained photosensitive emulsions with sub-microscopic crystals of silver bromide in gelatin have been developed. The emulsions have been prepared by controlling various factors such as concentration of gelatin and reactants, emulsification time and temperature, mixing procedures and addition of inhibitor, hardener and sensitizer. Flatness uniformity, coating thickness, grain size, fog, contrast, sensitivity and resolution of the photographic plates have been determined.

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 128-132

 

 

Kinetics and process parameter studies in the synthesis of 2-amino-1-butanol from methyl-DL-a -aminobutyrate

 

Sudip Mukhopadhyay+ & Sampatraj B Chandalia*

Chemical Engineering Division, University Department of Chemical Technology, University of Mumbai, Matunga,
Mumbai 400 019, India\

Received 25 October 1999; accepted 24 November 2000

Methyl-DL-a-aminobutyrate was hydrogenated in methanol at 105 atm hydrogen partial pressure and 170°C temperature over copper chromite catalyst in a high pressure autoclave to obtain 2-amino-1-butanol. Under best suitable reaction conditions, 100% selectivity was obtained at an ester conversion of 39%. Different important process parameters like temperature, catalyst loading, catalyst reusability, initial concentration, speed of agitation, and hydrogen partial pressure were studied. The reaction was found to be a first order reaction on the starting ester under the reaction conditions.

 

Indian Journal of Chemical Technology

Vol. 8,  March 2001 pp.133-139

 

Basic dyes removal from wastewater by adsorption on rice husk carbon

D K Singh & Bhavana Srivastava

Department of Chemistry, Harcourt Butler Technological Institute, Kanpur 208002, India.

Received 11 November 1999; accepted 13 November 2000

Rice husk carbon (RHC) has been prepared from rice husk impregnated with 50% H3PO4 and carbonised at 3000C. Its adsorption capacity has been tested for the decolourization of wastewater containing safranine and methylene blue. The effect of system variables such as concentration, temperature, pH, contact time, adsorbent dosage and particle size are investigated. Removal of dye has been found to increase with increase in dye concentration and pH of the solution. Kinetics of removal has been found to follow the first order rate expression. The adsorption isotherm data fitted both Freundlich and Langmuir adsorption isotherms. Thermodynamic studies show the adsorption to be an exothermic and spontaneous.

 

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 140-148

 

 

Synthesis and characterization of monomeric and polymeric dyes

Hari R Maradiyaa* & Vithal S Patelb

aV P & R P T P Science College, Vallabh Vidyanagar 388 120, India

bDepartment of Chemistry, Sardar Patel University, Vallabh Vidyanagar 388 120, India

Received 19 August 1999; accepted 30 October 2000

Monomeric dyes have been synthesized by the diazotization of 2-amino-3,5-bis(ethoxycarbonyl)-4-methylthiophene and coupled with various substituted N-arylmaleimides. The polymeric dyes have been derived from monomeric dyes by the free radical addition polymerization. The polymeric dyes are characterized by intrinsic viscosity, molecular weight by VPO and thermogravimetry. Monomeric and polymeric dyes also have been characterized by their IR spectra and elemental analysis. All the dyes are applied on nylon and polyester fibres as a disperse dye and their dyeing properties are studied.

 

 

Indian Journal of Chemical Technology

Vol. 8, March 2001, pp. 149-152

 

Effect of heating rate on the char yield and pore structure of chars prepared from viscose rayon cloth

K Kumar, R K Saxena & A K Sarkar*

Material Characterisation Division, National Physical Laboratory,

Dr K.S. Krishnan Road, New Delhi 110012, India

Received 24 March 1999; accepted 1 December 2000

Characteristics of the char prepared from viscose rayon cloth has been studied. Effect of heating rate in different temperature zones has been investigated. Rate of weight loss of the pretreated viscose rayon cloth varies with time throughout the temperature zone.

 

 

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