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
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
d) Livermorium is a natural radioactive element
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.
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.
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 is not the property of dioxygen gas
a) Dioxygen is a colourless and odourless gas.
b) Dioxygen is paramagnetic.
c) Dioxygen is diamagnetic.
d) Dioxygen is soluble in water which support aquatic life.
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
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
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
An antifreeze solution is prepared from 222.6 g of ethylene glycol \(C_2\)\(H_4\)\((OH)_2\) and 200 g of water. Calculate the molality of the solution. If the density of this solution be 1.072 \(gmL^{-1}\), what will be the molarity of the solution?
(a) 7.20 M
(b) 12.03 M
(c) 9.11 M
(d) 6 M
Which of the following is not true about the ionic solids?
(A) Bigger ions form the close packed structure.
(B) Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size.
(C) Occupation of all the voids is not necessary.
(D) The fraction of octahedral or tetrahedral voids occupied depends upon the radii of the ions occupying the voids.
Highest oxidation state of manganese in fluoride is +4 (MnF₄) but highest oxidation state in oxides is +7 (Mn₂O₇) because
(a) fluorine is more electronegative than oxygen.
(b) fluorine does not possess d-orbitals.
(c) fluorine stabilises lower oxidation state.
(d) in covalent compounds fluorine can formsingle bond only while oxygen forms double bond.
The molal elevation constant depends upon
(a) nature of solute.
(b) nature of the solvent.
(c) vapour pressure of the solution.
(d) enthalpy change.
Which of the following will have the maximum dipolemoment?
(a) \(CH_3\)F.
(b) \(CH_3\)Cl.
(c) \(CH_3\)Br.
(d) \(CH_3\)I.
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.
The difference between the electrode potentials of two electrodes when no current is drawn through the cell is called ___________.
a. Cell potential.
b. Electromotive Force.
c. Potential difference.
d. Cell voltage.