INDIAN SCHOOL MUSCAT
CLASS XII – CHEMISTRY WORK SHEET -1 – THE p-BLOCK ELEMENTS
1.
2.
3.
4.
5.
How is very pure nitrogen prepared?
Complete the following reactions:
i.
NH4CI(aq) + NaNO2(aq) →
ii.
NH4Cl + Ca(OH)2 →
iii. ZnSO4 aq + NH4OH aq →
iv. NaNO3 H2SO4 →
v.
Cu + HNO3(dilute) →
vi. Zn + HNO3(conc.) →
vii. S8 + HNO3(conc.) →
viii. P4 NaOH H 2O →
ix. PH4I KOH →
x.
Cu + H2SO4(conc.) →
xi. HCl  O2
xii. NH3 (excess) + Cl2 →
xiii. NaOH (cold , dil) + Cl2 →
xiv. Cl2 + NaOH (hot, Con) →
xv. U(s) + ClF3(l) →
xvi. XeF4 O2F2 →
xvii. XeF2 (s) + H2O(l) →
xviii. XeF6 + H2O →
xix. Na2SO3 + 2HCl →
Give equations for the manufacture of
a) Ammonia from nitrogen b) Nitric acid from ammonia c) Sulphuric acid from Sulphur
d) Chlorine from HCl
Draw the structures of XeF2, XeF4, XeF6, XeO3, XeOF4, SF4, PCl5(s), orthophosphoric acid,
metaphosphoric acid, pyrophosphoric acid, phosphorous acid, peroxodisulphuric acid,
iodine heptafluoride and perchloric acid
Explain why
i. Bond energy of F2 is lower than that of Cl2.
ii. Electron gain enthalpy of fluorine is less than that of chlorine.
iii. Fluorine is the most reactive among halogens.
iv. H2S is gas while water is liquid at room temperature.
v. H3PO3 is diprotic.
vi. HF has a higher boiling point than HCl.
vii. HI is a stronger acid than HCl.
viii. Maximum covalency of nitrogen is four.
ix. Nitrogen is a diatomic molecule while Phosphorous is tetra atomic.
x. Noble gases exhibit low chemical reactivity.
xi. Noble gases form compounds with oxygen and fluorine only.
xii. Fluorine forms only one oxo acid.
xiii. Halogens are coloured.
xiv. Sulphur at elevated temperatures exhibit paramagnetism.
xv. Unlike phosphorous, nitrogen has no tendency for catenation.
xvi. Pentavalent bismuth is a strong oxidising agent.
xvii. Bonds in PF5 are not equivalent.
xviii. Al does not react with nitric acid.
xix. Helium is used in diving apparatus.
xx. R3P=O exists but R3N=O does not.
xxi. PCl3 fumes in moisture.
xxii. SF6 is much less reactive than SF4.
6. Name a compound in which chlorine displays ‘+7’ oxidation number.
7. What happens when H3PO3 is heated?
8. Which compound led to the discovery of noble gas compounds?
9. Which of the xenon fluorides molecule is isoelectronic with IF5? Draw its structure.
10. Arrange the following according to the property mentioned. Give reason.
a. F2, Cl2, Br2, I2 (decreasing BDE)
b. H2S, H2O, H2Se, H2Te (decreasing thermal stability)
c. HF, HCl, HBr, HI (increasing acidity)
d. HF, HCl, HBr, HI (increasing stability)
e. NH3, PH3, AsH3, SbH3 (decreasing basic nature)
f. HOCl, HOClO, HOClO2, HOClO3 ( decreasing acidity)
g. H2S, H2O, H2Se, H2Te ( increasing boiling point)
h. NH3, PH3, AsH3, SbH3 (increasing boiling point)
i. HOCl, HOBr, HOI ( increasing acid character)
11. How are XeO3 and XeOF4 prepared?
12. What are interhalogen compounds? How are they prepared? Why are they more reactive
than molecular halogens?
13. Give a method of preparation of XeF6. Discuss its hydrolysis.
14. Compare bond angles in a) NH3 and PH3 b] H2S and H2O
15. Why should binary compounds of oxygen & fluorine be called oxygen fluorides & not
fluorine oxides?
16. Why does H3PO3 act as a reducing agent but H3PO4 does not.
17. Out of noble gases, only Xe is known to form chemical compounds.
18. Explain disproportionation reaction by giving an example.
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