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
a) more effective nuclear charge
b) presence of stable half-filled electronic configuration
c) smaller size
d) high electronegativity
b) presence of stable half-filled electronic configuration
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
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 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 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.
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.
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.
Assertion: The two strands of DNA are complementary to each other.
Reason: The hydrogen bonds are formed between specific pairs of bases.
A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.
The reaction \({\\(CH_3\\)}_2\)CHCl + NaI → \({(\\CH_3\\)}_2\)CHI + NaCl is known as –
a) Finkelstein’s reaction.
b) Stephen’s reaction.
c) Kolbe’s reaction.
d) Wurtz reaction.
The reaction R-Br + NaCN → R – CN + NaBr is an example of –
(a) Elimination Reaction.
(b) Nucleophilic Substitution.
(c) Electrophilic Substitution.
(d) Oxidation Reduction.
Acid catalysed dehydration of t-butanol is faster than that of n-butanol because
(a) tertiary carbocation is more stable than primary carbocation.
(b) primary carbocation is more stable than tertiary carbocation.
(c) t-butanol has a higher boiling point.
(d) rearrangement takes place during dehydration of t- butanol.
Order of esterification of alcohols are
(a) 3° > 1° > 2°.
(b) 2°> 3° > 1°.
(c) 1 ° > 2° > 3°.
(d) None of these.
Consider the figure and mark the correct option.
(a) water will move from side (A) to side (B) if a pressure lower than osmotic pressure is applied on piston (B).
(b) water will move from side (B) to side (A) if a pressure greater than osmotic , pressure is applied on piston (B).
(c) water will move from side (B) to side (A) if a pressure equal to osmotic pressure is applied on piston (B).
(d) water will move from side (A) to side (B) if pressure equal to osmotic pressure is applied on piston (A).
Which is the most reactive towards SN1 reaction –
a) \(C_6\)\(H_5\)\(CH_2\)Cl.
b) \(C_6\)\(H_5\)CH(\(C_6\)\(H_5\))Br.
c) \(C_6\)\(H_5\)CH(\(CH_3\))Br.
d) \(C_6\)\(H_5\)C(\(CH_3\))(\(C_6\)\(H_5\))Br.