The lowest boiling point of helium is due to its
a) Inertness
b) Gaseous nature
c) Weak van der Waals force between atoms
d) electronic configuration
a) Inertness
b) Gaseous nature
c) Weak van der Waals force between atoms
d) electronic configuration
c) Weak van der Waals force between atoms
On a large-scale nitric acid is prepared mainly by
a) Haber's process
b) Ostwald’s process
c) Contact Process
d) Deacon's process
Stability of hydrides of group 16 elements
a) increases down the group
b) decreases down the group
c) all hydrides are equally stable
d) none of the above
When Xe reacts with Fluorine in 1:5 ratio at 873 K it forms
a) \(XeF_2\)
b) \(XeF_4\)
c) \(XeF_6\)
d) \(XeOF_4\)
Identify the correct order of acidic strength for H-X
a) HCl > HBr > HI.
b) HCl > HI > HBr.
c) HI > HCl > HBr.
d) HI > HBr > HCl.
Chlorine water on standing loses its yellow colour due to the formation of
a) Cl and HOCl.
b) HCl and HOCl.
c) HOCl and \(HOCl_2\).
d) HCl and \(HOCl_2\).
\(SO_2\) is ----------and \(TeO_2\) is -------- agent
a) reducing, an oxidising
b) an oxidising, reducing
c) reducing, reducing
d) an oxidising, an oxidising
Hypochlorous acid and perchloric acid are, respectively:
a) HOCl and \(HClO_4\).
b) HOCl and \(HClO_3\).
c) \(HClO_2\) and \(HClO_3\).
d) \(HClO_2\) and \(HClO_4\).
Which one is not correct statement?
a) Nitrogen does not form pentahalide due to non-availability of the d orbitals in its valence shell
b) Pentahalides are more covalent than trihalides.
c) In case of nitrogen, only \(NF_3\) is known to be stable
d) Trihalides except \(BiF_3\) are predominantly ionic in nature
Which statement correct about halogens?
a) They are all diatomic and form univalent ions.
b) They are all capable of exhibiting several oxidation states.
c) They are all diatomic and form diatomic ions.
d) They are all reducing agents.
Which is incorrect statement.
a) Oxygen is the most abundant of all the elements on earth
b) Organic materials such as eggs, proteins, garlic, onion, mustard, hair and wool contain sulphur
c) Selenium and tellurium are found as metal selenides and tellurides in sulphide ores
d) Livermorium is a natural radioactive element
The electronic configuration of Cu(II) is 3d⁹ whereas that of Cu(I) is 3d¹⁰. Which of the following is correct?
(a) Cu(II) is more stable
(b) Cu(II) is less stable
(c) Cu(I) and Cu(II) are equally stable
(d) Stability of Cu(I) and Cu(II) depends on nature of copper salts
Order of esterification of alcohols are
(a) 3° > 1° > 2°.
(b) 2°> 3° > 1°.
(c) 1 ° > 2° > 3°.
(d) None of these.
When KMnO₄ solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because
(a) CO₂ is formed as the product.
(b) The reaction is exothermic.
(c) MnO₄⁻ catalyses the reaction.
(d) Mn²⁺ acts as an auto-catalyst.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?