In the Dewar's method of separation of noble gases, the mixture of noble gases is kept in contact with coconut charcoal at 173K. Which one of the following gaseous mixtures is not adsorbed on to the charcoal ?
A. Ar, Kr
B. Xe, Ar
C. He, Ne
D. Xe, Kr
The number of oxygen atoms bonded to one phosphorus atom in P4O6 is:
A. 4
B. 3
C. 6
D. 5
Which of the following is not correct
A. SiO2 is used as acid flux
B. The distance between the layers in graphite is 3.35 x 10-3 cm
C. SiO2 reacts with Na2CO3 and liberates CO.
D. The hybridization of C in graphite is sp2
Which of the following is not correct
A. Ammonia is used as refrigerant
B. A mixture of Ca(CN)2 and C is known as nitrolim
C. A mixture of Ca(H2PO4)2 and CaSO4.2H2O is known as superphosphate of lime
D. Hydrolysis of NCI3 gives NH3 and HOCl
The molecular formula of potash alum is :
A. KAI2S4H48O40
B. K2AI2S4H48O39
C. K2AI2S4H48O40
D. KAI2S4H48O40
In Fischer-Ringe's method of separation of nobles gas mixture, from air is used
A. 90% CaC2 + 10% CaCl2
B. Coconut charcoal
C. Soda lime + potash solution
D. 90% CaCO3 + 10% urea
Observe the following statements regarding purification of bauxiteI. During Hall's process, silica is removed as Si (vapour)II. Bauxite ore contaminated with Fe2O3 is purified in Baeyer's processIII. During Serpeck's process, AlN is formedThe correct answer is
A. I, II and III are correct
B. Only I and II are correct
C. Only I and III are correct
D. Only II and III are correct
Which of the following is not correct
A. Iodine oxidises sodium thiosulphate to sodium tetrathionate
B. Sodium thiousulphate is soluble in water
C. Ozone is used to identify the presence of unsaturation in alkenes
D. Sodium thiosulphate reacts with iodine to form sodium sulphate
Which one of the following pairs of reactants does not form oxygen when theyreact with each other
A. F2, NaOH solution (hot, conc.)
B. F2, H20
C. Cl2, NaOH solution (cold, dilute)
D. CaOCl2, H2S04 (dilute, small amount)
The chemical formula of feldspar is
A. KAlSi3O8
B. Na3AlF6
C. NaAlO2
D. K2SO4 . Al2(SO4)3 . 4Al(OH)3
The formula of the product formed, when sodium thiosulphate solution is added to silver bromide is
A. Ag2S2O3
B. Ag2S
C. Na3[Ag(S2O3)2]
D. Ag3[Na(S2O3)2]
The following are some statements related to VA group hydrides,I . Reducing property increases from NH3 to BiH3.II..Tendency to donate lone pair decreases from NH3 to BiH3III.Thermal stability of hydrides decreases from NH3 to BiH3.IV. Bond angle of hydrides decreases from NH3 to BiH3.The correct statements are
A. I, II, III and IV
B. I, III and IV
C. I, II and IV
D. I and IV
Which one of the following noble gases is used in miner's cap lamps
A. Helium
B. Neon
C. Argon
D. Krypton
Which of the following is not a peroxy acid
A. Perphosphoric acid
B. Pernitric acid
C. Perdisulphuric acid
D. Perchloric
Calorific value of producer gas is low because of
A. high percent of N2
B. low percent of CO2
C. high percent of CO
D. low percent of N2
Which of the following is used for making optical instruments ?
A. SiO2
B. Si
C. SiH4
D. SiC
CFCl3 is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen ?
A. Cl2
B. Cl-
C. F-
D. Cl+
What is the correct order of occurrence (% by weight) in air of Ne, Ar and Kr ?
A. Ne > Ar > Kr
B. Ar > Ne > Kr
C. Ar > Kr > Ne
D. Ne > Kr > Ar
Observe the following statements :I. Bleaching powder is used in the preparation of chloroform.II. Bleaching powder decomposes in the presence ofCoCl2 to liberate 02.III.Aqueous KHF2 is used in the preparation of fluorine.The correct combination is :
A. I , II and II are correct
B. Only II is correct
C. Only I and III are correct
D. Only I and II are correct
Hydrolysis of NCI3 gives NH3 and X. Which of the following is X ?
A. HClO4
B. HClO3
C. HOCl
D. HClO2
Fluorine reacts with dilute NaOH and forms a gaseous product A. The bond angle in the molecule of A is
A. 1040 40'
B. 1030
C. 1070
D. 1090 28'
The type of bonds present in sulphuric anhydride
A. 3 σ and three pπ -dπ
B. 3 σ, one pπ - pπ and two pπ - dπ
C. 2 σ and three pπ-dπ
D. 2 σ and two pπ-dπ
Which pair of oxyacids of phosphorous contain ‘P - H' bonds
A. H3PO4, H3PO3
B. H3PO5, H4P2O7
C. H3PO3, H3PO2
D. H3PO2 , HPO3
SiCl4 on hydrolysis forms X and HCI. Compound X loses water at 1000oC and gives Y. Compounds X and Y respectively are
A. H2SiCl6 , SiO2
B. H2SiO4 ,Si
C. SiO2 , Si
D. H4SiO4 ,SiO2
Aluminium reacts with NaOH and forms compound X. If the coordination number of aluminium in X is 6, the correct formula of X
A. [Al(H2O)4(OH)2]+
B. [Al(H2O)3(OH)3]
C. [Al(H2O)2(OH)4]-
D. [Al(H2O)6](OH)3
Helium mixed with oxygen is used in the treatment of:
A. Beri beri
B. burning feet
C. Joints burning
D. Asthma
While phosphorus form PCl5, nitrogen does not form NCl5 because
A. Nitrogen is more electro negative than phosphorus
B. Nitrogen atom is smaller than phosphorus
C. The ionisation energy of nitrogen is greater than that of phosphorus
D. Unlike phosphorous, nitrogens has no d-orbital in its valence shell