24i dont have ans of Q3..so trusting u[1]
Q1 FeI3 doesnt exist becoz ?
Q2 MnO2 dissolves in conc. HCl to form ?
Q3 In which of the following ,color is due to charge transfer ?
a)[Mn(OH)4]2-
b)MnO42-
c)MnO2
-
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8 Answers
19ans 3> b
OXYSALTS of some of the transition elements ,e.g.KMnO4 and K2Cr2O7 are coloured though the central atom does not contain any unpaired electrons . the colour of thees compounds arises due to CHARGE TRANSFER SPECTRUM (colour is associated with the electrons being promoted from one energy level to another , and absorbing or emitting the energy difference between the two levels . thus transfer of an electron from M to L or vice versa results in charge transfer which gives rise to spectra .such spectra are called charge transfer spectra) . Ag+ does not contain any unpaired electrons but some of the compounds of silver are coloured which can be explained on the basis of ionic character . when the ionic character of these ionic compounds is less than 20% , then the compound will be coloured.
3Q2) i guess MnO+Cl2 +H2O
q1)FeI3 doesnt exists bcos electronegativity of iodine is less compared to chlorine.
11Ans 1) Fe I 3 does not exist in a pure state bcoz Fe 3+ oxidizes I - . In solution this oxidation is complete but some Fe I 3 may exists with Fe I2 in the solid.
11Ans 2) Mn O2 does not reacts with most acids unless heated. It dissolves in conc H Cl,. but does not form Mn 4+ in the soln. Instead it oxidizes Cl - to Cl 2 and is itself reducued to Mn 2+.
Mn O 2 + 4 H+ + 4 Cl - → Mn 2+ + 2 Cl - + Cl2 + 2H2O
This was the commercial method of producing Cl 2
24tush ur ans is rite...
but why Mn O2 does not reacts with most acids unless heated ???
1eure, u r rite. but, here pure MnO2 doesn't react, but the impure form, i.e. pyrolusite ore reacts.
it even reacts with conc. HBr to form Br2 gas. this are the standard reactions of formation of Cl2 and Br2.
24aieeee
"it even reacts with conc. HBr to form Br2 gas. this are the standard reactions of formation of Cl2 and Br2."
here it means pure form or impure form ?