chemistry

EAMCET QUESTIONS FROM CHAPTER  NOBLE GASES PART-1

1.The number of pπ −dπ ‘pi’ bonds present in XeO₃ and XeO₄ molecules, respectively

1) 3, 4                         2) 4, 2                          3) 2, 3                         4) 3, 2

2.Which of the following statements is not correct ?

1)  In the Dewar’s method for the separation of noble gases, activated coconut charcoal is used.

2)  Krypton is used in miners cap lamps.

3)  The electron affinity values of noble gases are nearly equal to zero.

4) Xenon gives different colours when mixed with mercury vapour.

3.Which of the following statements about Noble gases are correct ?

(I) XeO₃is an explosive tetrahedral molecule.

(II) In fisher Ringe method, a mixture of CaCl₂and CaC₂ is used to remove N₂and O₂. (III) He and Ne are chemically inert due to lack of d-orbitals and high ionization potential. IV) At 173 K he and Ne are adsorbed on activated charcoal.

The correct answer is

1) I and II                  2) II and III                3) II,III and IV          4) I,II, III and IV

4.In the separation of noble gas mixture from air by Ramsay Rayleigh’s first method, the substances used for

the removel of	and O2 respectively are
1) Cu and Mg	2) Mg and Cu	3) C and CaC2	4) KOH solution

5.Which one of the following noble gases is used in miner’s cap lamps ?

1) Helium                   2) Neon                       3) Argon                     4) Krypton

6.What is the correct order of occurrence (% by weight) in air of Ne, Ar and Kr ?

	1) Ne > Ar > Kr		2)		3)		4)
7	In Fischer-Ringe's method of separation of noble gases mixture from air, _____ is used.
					σπ 3  2
					CaC90%NXeArFO> CaCOKrNe+10%>KrANeCaCl+
	(1) 90%				sp2 d423	3	2
					(2) Coconut charcoal
	(3) Sodalime + potash solution				(4)		urea
8.	Which of the following is not correct?
	(1)	has four	and four		bonds.
	(2) The hybridization of			in	is

(3) Among noble gases, the occurance (present by weight) of argon is highest in air.

(4) Liquid helium is used as Cryogenic liquid.