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20. Treatment of an 8.00g sample containing 23. Which of the following is the highest
a lead ore with excess sulphuric acid yields energy transition in an organic compound?
4.75g of lead (II) sulphate.
(A) n to σ*
The correct expression for the percentage (B) n to *
of lead in the sample is (C) σ to *
(D) π to *
x 100
(A) 207 x 8.00
303 x 4.75
Item 24 refers to the following structure of
x 100
(B) 303 x 4.75 caesalpinin.
303 x 8.00
207 x 4.75
(C) x 100
303 x 8.00

(D) 303 x 8.00
x 100
207 x 4.75

21. Which region of the electromagnetic
spectrum below provides the required The compound caesalpinin exhibits absorp
-1
energy for n.m.r spectroscopy? tion at wave numbers 3400 cm and 1750
-1
cm in the IR spectrum.
24. Which functional groups are responsible
for these absorptions?

(A)
22. Which is the correct sequence of steps for
the detection of the concentration of heavy
metals in marine sediments by Atomic (B)
Absorption Spectroscopy (AAS)?

(A) Concentration of sample solution (C)
→ aspiration → atomisation
(B) Concentration of sample solution
→ atomisation → aspiration (D)
(C) Aspiration → concentration of
sample solution → atomisation
(D) Atomisation → concentration of
sample solution → aspiration

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02212010/SPEC/CAPE 2017