In preparation of sulphuric acid from sulphur dioxide in lead chamber process. What substance is used as a catalyst?
Manganese dioxide
Vanadium pentoxide
Nitric oxide
Raney nickel
Which halogen has the highest value of negative electron gain enthalpy?
Fluorine
Chlorine
Bromine
Iodine
Freon 12 is manufactured from CCl4 by
Wurtz reaction
Swarts reaction
Fittig reaction
Wurtz-Fittig reaction
Which one of the following group 16 elements does not exist in -2 oxidation state?
S
Se
O
Po
D.
Po
In the group 16, most metallic element does not show -2 oxidation state as its electronegativity is very low.
Hence, Po (polonium) (Z = 84) does not show -2 oxidation state because on· going down the group, electropositive nature increases.
In which one of the following compounds of xenon, highest number of lone pair of electrons is present in xenon?
XeF6
XeF4
XeF2
XeOF3
Which one of the following statements is not true in respect of propeties of interhalogen compounds?
They are all covalent compounds
They are volatile solids or liquids except ClF
IF5 has square pyramidal structure
They are all paramagnetic in nature
Which of the following noble gases has the nighest positive electron gain enthalpy value?
Helium
Krypton
Argon
Neon
Oxyacids of phosphorus and the starting materials for their preparation are given below.
Oxyacid | Materials for preparation |
A. H3PO2 | i. Red P + alkali |
B. H3PO3 | ii. P4O10 + H2O |
C. H3PO4 | iii. P2O3 + H2O |
D. H4P2O6 | iv. White P + alkali |
Choose the correct answer from the codes given below
A - iv; B - iii; C - ii; D - i
A - i; B - iii; C - ii; D - iv
A - iv; B - iii; C - i; D - ii
A - ii; B - iii; C - i; D - iv