sure shot of inorganicl chemistry

INORGANIC CHEMISTRY
CLASS XII
TIME : 3 HRS M.M. 70
General Instructions :
All questions are compulsory
Ques No. from 1 to 8 carry 1 marks, 9 – 18 carry 2 marks, 19 – 27 carry 3 marks, 28-30 carry 5 marks
Use log table if necessary.
Why should not medicines be taken without consulting doctors.
Give one example of hexadentate ligand. Give its use.
Name the chemicals responsible for the antiseptic properties of dettol.
Why are cr2+ of reducing and Mn3+ oxidising when both have d4 configuration.
Give balanced equations for preparation of K2Cr2O7 from Chromatic ore.
How does Ammonia react with a solution of cu2+.
Why does Pcl3 fume in moisture.
Why do transition metal ions have high enthalpy of hydration.
Why do noble gases have comparatively large atomic sizes.
Mention one important use of each of the following :
a) Equanil b) Sucralose
11. Why tetrahedral complexes not show geometrical isomerism but show optical isomerism.
OR
[Fe(CN)6]4- and [Fe(H2O)6]2+ are of different colours in dilute solution. Why?
Why do actinides in general exhibit a greater range of oxidation states, than the lthanoides.
Write the balanced equations for the following reactions :
a) P4 + KOH + H2O
b) SF4 + H2O
Name two poisonous gases which can be prepared from chlorine gas.
a) Name the method used for refining of
i) Nickel ii) Zircoium
b) The extraction of Au by leaching with NaCN involves both oxidation and reduction. Justify.
16. Why Fluorine is a stronger oxidising agent than chlorine.
17. Why is the reduction of a metal oxide easier if the metal formed is in liquid state at the temperature of reduction.
18. Give the electronic configuration of the :
a) d – orbitals of Ti in [Ti(H2O)6]3+ ion in the octahedral crystal field.
b) Why is this complex coloured ? Explain ( e- in d orbital)
19. a) Name a broad spectrum antibiotic and state two diseases for which it is prescribed.
b) Why is biothional added to the toilet soap.
20. Account for the following :
a) On addition of ozone gas to Kl solution. Violet vapours are obtained.
b) H3PO2 and H3PO3 act as good reducing agents white H3PO4 does not.
c) Chlorine water has both oxidising and bleaching properties.
21. What are antihistamines? How do they act on human body. Give two examples.
OR
Account for the following :
Aspirine drug helps in the prevention of heat attack.
Diabetic patients are advised to take artificial sweetness instead of natural sweetness.
Detergents are non biodegradable while soaps are biodegradable.
22. What is the significance of leaching in the
a) extraction of aluminium
b) Why are sulphide and carbonate ores converted into oxides.
23. a) Explain the cause and two consequences of lanthanoid contraction.
b) Give balanced chemical equation of two reactions in which KMnO4 acts as an oxidising agents in the acidic medium.
24. Predict the shape of the following molecules :
a) XeF6 b) ClF3 c)XeO3
25. a) Explain by hydrate isomerism in coordination compounds. Give an example.
b) NH3 is strong ligand. NH4+ ion is not why?
c) Draw all the optical isomers of [COcl(Cn)2(NH3)]2+.
26. Name the chief ores of Zinc and Mercury. Describe the reactions involved in the extraction of these metals from the respective ores.
27. Explain the following :
a) Thermit process is quite useful for repairing the broken parts of a machine.
b) Aquous solution of sodium chloride cannot be used for the isolation of sodium by electrolytic reduction method.
c) Carbon reduction process is not applied for reducing aluminium oxide to aluminium.
28. a) Write the name and draw the structure of each of the following complex compounds :
i) [Co (NH3)4(H2O)2]Cl2
ii) [Pt(NH3)4][NiCl4]
b) Explain as to how the two complexes of nickel [Ni(CN)4]2- and Ni(CO)4; have different structure but do not differ in their magnetic behaviour (Ni = 28)
OR
How is magnitude o affected by affected by
nature of ligand and
oxidation state of metal ion
Write the formula for the following co ordination compounds
Di chloridobis (ethane – 1,2 diamine) cobalt (iii)
Tetra ammine aquachloride cobalt (iii) cobalt
Potassium tetra hydroxyzincate (ii)
29. a) Describe the chemical reactions involved in manufacture of sulphuric acid by contact process.
b) Give the formula and describe the structure of noble gas species which is isostructural with
i) IBr2- ii) ICl4 iii) BrO3-
OR
Account for the following :
Sulphur in the vapour state is paramagnetic. Why?
Why SF6 is resistant to hydrolysis.
Bleaching of flowers by chlorine is permanent while that by sulphur dioxide is temporary explain.
PCl5- act as a chlorinating agent.
Bismith is a strong oxidising agent in the pentavalent state.
30. Give reasons :
a) The lower oxidation state of Mn is basic while the higher is acidic.
b) Mn (II) shows maximum paramagnetic character amongst divatent ions of first transition series.
c) In titration of FeSO4 with KMnO4 in acidic medium. Why is dil H2SO4 used instead of dil HCl.
d) Ce4+ is used as oxidising agent in volumetric analysis.
e) Zn2+ salts are white cu2+ salts are blue.
OR
CrO42- is strong oxidising agent while MnO42- is not.
Out of Ag2SO4, CuF2, MgCl2 and Cucl which would be coloured and why?
The radius of Fe2+ (z = 26) is less than that of Mn2+ (z = 25)
The lowest oxide of transition metal is basic, the highest is acidic.
The highest oxidation states is exhibited oxoanion of a soild.