Chemistry paper 4 (urgent help needed!!!)

[diwash]

May/june 07 Qno 4 C(I)
http://www.xtremepapers.me/CIE/International A And AS Level/9701 - Chemistry/9701_s07_qp_4.pdf

Oct/nov 09 Qno 3(b)
http://www.xtremepapers.me/CIE/International A And AS Level/9701 - Chemistry/9701_w09_qp_41.pdf

 

[kahynickel]

FOR J7

This is an absorbance spectra. If a complex absorbs in a yellow region it will reflect blue.

For C: it absorbs strongly in the green region therefore the it will reflect RED.

For D: it absorbs in the yellow region therefore the it will reflect BLUE.

Remember if green is absorbed it emit its complementary color i.e RED. You should know the complementary color.

FOR NOV 09 q.3 (b)

(i) You should know the colors from the reactions of Cu2+(aq).

(ii) In [Cu(NH3)4(H2O)2]2+ due to NH3 which absorbs strongly in the yellow region (590nm) of the visible region of the electromegnetic spectrum so appears as dark blue, while [Cu(H2O)6]2+ absorbs less in that region hence pale blue.

(iii) the number of NH3 as ligands are increasing thus the spectrum of this complex should be between these two i.e the hump is at between 580-800nm.

 

[diwash]

thanks man...