Analytical chemistry

Analytical chemistry: separation, spectroscopic, electro- and thermoanalytical methods.

YEAR JUN-2016 DEC-2015 JUN-2015 DEC-2014 JUN-2014 DEC-2013 JUN-2013 DEC-2012 JUN-2012 DEC-2011 JUN-2011
No.of questions appeared  3   2 3 2 4 3 3 3 2 1 1

1.The spectrophotometric response for the titration of a mixture of Fe3+and Cu2+ions against EDTA is given below.

anylytical-spectrometric-edta-csir-net-gate-chemical-sciences-june-2012

The correct statment is:

(a) Volume ab≡ [Fe3+]and volume cd ≡ [Cu2+]

(b) Volume ab≡ [Cu2+]and volume cd ≡ [Fe3+]

(c) Volume ab≡ [Fe3+]and volume ab≡excess EDTA

(d) Volume ab≡ [Cu2+]and volume cd ≡excess EDTA

.

 

2.The quantitative determination of N2H4 with KIO3 proceeds in a mixture of H2O/CCl4 as follows

N2 H4 +KIO3+2HCl —-> N2 +KCl+ICl+3H2O

The end point for the titrimetric reaction is:

(a) Consumption of N2H4

(b) ICI formation

(c) Disappearance of the yellow color due to Cl2 in CCl4 layer.

(d) Displacement of the rod color due to I2 in CCl4 layer.

 

3.Appropriate reasons for the deviation form the Beer’s law among the following are

(a) Monochromaticity of light

(C) Very high concentration of analyte

(B) Association of analyte

(D) Dissociation of analyte.

(1) A, B and D

(b) B, C and D

(c) A, C and D

(d) A, B and C

 

4.On subjecting 9.5 ml solution of Pb2+of X M to polorographic measurements, Id was found to be 1 µA. When0.5 mL of 0.04 M Pb2+was added before the measurement, the Id was found to be 1.25 µA.

(1) 0.0035

(b) 0.0400

(c) 0.0067

(d) 0.0080

 

5.A solution of 2.0 g of brass was analysed for Cu electrogravimetrically using Pt-gauze as electrode. The weight of Pt-gauze changed from 14.5g to 16.0 g. The percentage weight of Cu in brass is

(a) 50

(b) 55

(c) 60

(d) 75

 

6.In a polarographic measurement, (aqueous KCl solution used as supporting electrolyte) anapplied potentialmore than +0.4 V, results mainly in the formation of

 (a) HgI

(b) HgII

(c) Cl2

(d) O2

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