CBSE Class 12 Chemistry Sample Paper – p- BLOCK ELEMENTS

MM : 30                            TIME : 40 MIN.
1. PCl5 is ionic in nature in solid state .Explain.
2. Out of NH3 and PH3 which one is more basic and why?
3. Explain why nitric oxide shows different behavior in gaseous and liquid state?
4. Explain why both N and Bi do not form pentahalides while phosphorus does ?
5. What is electron gain enthalpy ? Why its value for S is higher than O?
6. SF4 undergo hydrolysis but not SF6 why?
7. Why Fluorine does not exhibit positive oxidation state?
8. What are interhalogen compounds ? Why they are more reactive than halogens ?
9. Addition of Cl2 to KI solution give it a brown colour but excess of Cl2 turns it colourless. Why?
10.Explain why only Xe can form different types of compounds from all noble gases ?
11.Why CO2 exist as a gas but SiO2 act as solid at room temperature ?
12.Explain why SO2 act as oxidising agent as well as reducing agent but SO3 can act as only oxidising agent ?
13.Write balanced equation for the following
(i) NaCl is heated with sulphuric acid in the presence of MnO2 .
(ii) Cl2 gas is passes into a solution of NaI in water .
14.How are XeO3 and XeO4 prepared ?
15.Complete the following equations :
(i) NaOH (aq) + Cl2 ( aq) →
(ii) P4 + NaOH (aq) + H2O→

 

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