Which is the correct statement?
a) valence shell electronic configuration of group 16 elements is \(ns^1\)\(np^4\).
b) the elements of group 16 have lower ionisation enthalpy values compared to those of Group 15 in the corresponding periods.
c) Oxygen atom has more negative electron gain enthalpy than sulphur.
d) oxygen has the highest electronegativity value amongst the elements.
a) valence shell electronic configuration of group 16 elements is \(ns^1\)\(np^4\).
b) the elements of group 16 have lower ionisation enthalpy values compared to those of Group 15 in the corresponding periods.
c) Oxygen atom has more negative electron gain enthalpy than sulphur.
d) oxygen has the highest electronegativity value amongst the elements.
b) the elements of group 16 have lower ionisation enthalpy values compared to those of Group 15 in the corresponding periods
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 ionisation enthalpy of the group 15 elements is much greater than that of group 14 elements in the corresponding periods. Which is the most suitable reason?
a) more effective nuclear charge
b) presence of stable half-filled electronic configuration
c) smaller size
d) high electronegativity
Which of the following statement is false?
a) Radon is obtained from the decay of radium
b) Helium is an inert gas
c) Xenon is the most reactive among the rare gases
d) The most abundant rare gas found in the atmosphere is helium
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.
The idea that promoted to Bartlett to prepare first ever compound of Noble gases was
a) Low bond dissociation enthalpy of F-F bond in \(F_2\).
b) High bond enthalpy of Xe-F bond.
c) Ionization enthalpies of \(O_2\) and Xe are almost same.
d) None of the above.
There is a considerable increase in covalent radius from N to P. However, from As to Bi only a small increase in covalent radius is observed. This is due to
a) Increase in number of shells
b) increase in valence electrons
c) increase in ionisation enthalpy
d) the presence of completely filled d and/or f orbitals
Fructose contains functional group-
(a) Aldehyde
(b) Ketone
(c) Carboxylic acid
(d) primary amine
The order of reactivity of the following alcohols with halogen acids is
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.
An alcohol X when treated with hot conc. \(H_2\)\(SO_4\) gave an alkene Y with formula \(C_4\)\(H_8\). This alkene on ozonolysis gives single product with molecular formula \(C_2\)\(H_4\)O. The alcohol is
(a) butan-1-ol.
(b) butan-2-ol.
(c) 2-methylpropan-1-ol.
(d) 2,2-dimethylbutynal-1-oI.
Why is Helium used in divers' tank but not hydrogen gas?
a) Helium is lighter than hydrogen.
b) Helium is inert to any chemical reactions.
c) Helium is cheaper.
d) Helium is easy to get from market.
How is electrical conductance of a conductor related with length and area of cross-section of the conductor?
a. G = \(l. a.k^{-1}\)
b. G = \(k. l.a^{-1}\)
c. G = \(k.a. l^{-1}\)
d. G = \(k. l.a^{-2}\)
What would be the reactant and reagent used to obtain 2, 4-dimenthyl pentan-3-ol?
(a) Propanal and propyl magnesium bromide.
(b) 3-methylbutanal and 2-methyl magnesium iodide.
(c) 2-dimethylpropanone and methyl magnesium iodide.
(d) 2-methylpropanal and isopropyl magnesium iodide.