JEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2113
Discuss the pattern of variation in the oxidation states
of B to Ti Answer:
Element
| read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2114How can you explain higher stability of BCl3 as
compared to TlCl3? Answer: Boron exhibits only +3 oxidation state. So, it forms BCl3,
a stable compound. On moving down the group, the inert pair effect becomes
more and more pronounced therefo... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2115Why does Boron trifluride behave as a Lewis acid? Answer: BF3 being electron deficient, is a strong Lewis
acid. It reacts with Lewis bases easily to complete the octet around boron.
HINT: Lewis acids have a tendency to except electrons,... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2116Explain what happens when boric acid is heated? Answer: Boric acid, on heating loses water in three different temperatures
ultimately giving boron trioxide.
... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2117Suggest a reason as to why CO is poisonous? Answer: Carbon monoxide reacts with hemoglobin and form a stable
compound carboxyhemoglobin is 300 times more stable than oxyhemoglobin.
Formation of carboxyhemoglobin reduces the oxygen carrying ca... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2118Write the reaction of justify amphoteric nature of
aluminium. Answer: As dissolves both in acids and alkalies evolving
dihydrogen and thus, shows amphoteric nature.
... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2119Write the resonance structures of and Answer: Resonance structure of ion:
Resonance structure of ion:
... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2120Suggest reason why the B -----F bond lengths in BF3
(130 pm) and (143
pm) differ? Answer: In BF3, boron is sp2 hybridized. It has a
vacant 2p-orbital.Each fluorine in BF3 has completely filled
unutilized 2p-orbitals. Since, both of these... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2121How is excessive content of CO2 responsible for
global warming? Answer: CO2 is a green house gas. About 75% of the
solar energy reaching the earth is absorbed by the earth’s surface. The rest
of the heat radiates back to the atmosphere. But ... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2122Explain why is there a phenomenal decrease in ionization
enthalpy from carbon to silicon? Answer: As we move from carbon to silicon atomic size increases.
i.e., The distance between the outermost electron and nucleus increases. Thus
this ele... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2123How would you explain the lower atomic radius of Ga as
compared to aluminium? Answer: Electronic configuration of Al and Ga are as
The screening tendency of d-electrons is poor. Thus, on
moving from Al to Ga, shielding effect of 10d-electr... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2124What are allotrops? Sketch the structure of allotrops of
carbon mamely diamond and graphite. What is the impact of structure on
physical properties of two allotrops? Answer: The phenomenon of existence of an element in two or more
forms whic... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2125What do you understand by
(a) Inert pair
effect
(b) Allotropy
(c) Catenation? Answer: (a) Inert pair
effect: it is defined as the tendency of s- elections to remain togeth... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2126Draw the structures of BCl3. NH3 and AlCl3 (dimer). Answer:
... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2127Give reason for the following.
CCl4 is immiscible in water, whereas SiCl4
is easily hydrolyzed. Answer: Carbon tetrachloride (CCl4) is a covalent
compound while H2O is a polar compound and CCl4 does
not form H - bond with water molecule. ... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2128Give reason for the following.
Carbon has a strong tendency for catenation as compared to
silicon. Answer: The catenation is maximum in carbon and decreases down the
group. With increase in atomic size, electronegativity decrease, and due to... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2129Explain the following.
CO2 is a gas whereas SiO2 is a
solid. Answer: CO2 has a linear structure. Its dipole moment is zero. It
is believed that CO2 molecule is a resonance hybrid of following structures
sp hybridised
... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2130Explain the following.
Boron does not exist as B3+ ion. Answer: Due to small size of Boron, the sum of its first three
ionization enthalpies is very high. This prevents it to form +3 ions and
forces it to form only covalent compound. That’s ... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2131PbX2 is more stable than PbX4. Answer: Due to inert pair effect, Pb in + 2 oxidation state is
more stable than in + 4 oxidation state, hence, PbX2 is more
stable than PbX4.... read moreJEE-Main - Grade 11 - Chemistry - The p-block elements - Study ref# 2132Carbon shows catenation property but lead does not. Answer: Due to inert pair effect TI in +1 oxidation state is more
stable than that of +3 oxidation state. Therefore, TI(NO3)3
acts as an oxidizing agent.... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9814On addition of conc.to a chloride salt,
colourless fumes are evolved but in case of iodide salt, violet fumes come
out. This is because
(a) reduces to HI to I2
(b) HI of violet colou... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9815Which of the following elements can be
involved in pπ – dπ bonding?
(a) Carbon
(b) Nitrogen
(c) Phosphorus
(d) Boron Answer: (c) Among given four elements i.e.,
carbon, nitrogen, phosphorus and boron. Only phosphorus has v... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9816Which of the following pairs of ions are
isoelectronic and isostructural?
(a)
(b)
(c) read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9817Affinity for hydrogen decreases in the
group from fluorine to iodine. Which of the halogen acids should have highest
bond dissociation enthalpy?
(a) HF
(b) HCI
(c) HBr
(d) HI Answer: read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9818On heating with concentrated NaOH
solution in an inert atmosphere of CO2, white phosphorus gives a
gas. Which of the following statement is incorrect about the gas?
(a) It is highly poisonous and has smell
like rotten fish.
(b) It’solu... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9819Which of the following acids form three
series of salts?
(a)
(b)
(c)
(d) read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9820Maximum covalency of nitrogen is ……….. .
(a) 3
(b) 5
(c) 4
(d) 6 Answer: (c) Maximum covalency of nitrogen is 4 in
which one electron is made available by s-orbital and 3 electrons are made
available by p orbitals. H... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9821A brown ring is formed in the ring test
for ion. It is due to the
formation of
(a)
(b)
(c) read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9822Which of the following is not tetrahedral
in shape?
(a)
(b)
(c)
(d) read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9823In the preparation of compounds of Xe,
Bartlett had taken as a base
compound. This is because
(a) both O2 and Xe have same
size.
(b) both O2 and Xe have same
electron gain enthalpy.
(c) both O2 and Xe have almost
same ioni... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9824Which of the following is isoelectronic
pair?
(a)
(b)
(c)
(d) read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9825Which of the following statements are
correct?
(a) All the three N – O bond lengths in are equal.
(b) All P – Cl bond lengths in PCl5
molecule in gaseous state are equal.
(c) P4 molecule in white
phosphorus have regular strain there... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9826Which of the following statements are
correct?
(a) S – S bond is present in
(b) In peroxosulphuric acid Sulphur is in +6
oxidation state
(c) Iron powder along with and K2O is
used as catalyst in the preparation of NH3 by Haber’s ... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9827In the preparation of by contact process, why
is not absorbed directly
in water to form? Answer: In contact proces... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9828Write a balanced chemical equation for
the reaction showing catalytic oxidation of by atmospheric oxygen. Answer: Ammonia () on catalytic by
... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9829In, phosphorus is in hybridized state but
all its five bonds are not equivalent. Justify your answer with reason. Answer: It has trigonal bipyramidal geometry, in
which two Cl atoms occupy axi... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9830Why is nitric oxide paramagnetic in
gaseous state but the solid obtained on cooling it is diamagnetic? Answer: In gaseous state, NO2 exists
as a monomer which has one unpaired electron but in solid state, it dimerises
to N2O4 so no unpaired ... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9831Give one reason to explain why exists butdoes not exist? Answer: Existence of and can be explained on
the basis of size of central atom. Because fluorine is electronegative as
compared to chl... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9832Out of and, which one has higher
bond angle and why? Answer: Bond angle of (H – O – H =
104.5̊) is larger than that of read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9833is known but is not. Why? Answer: Fluorine atom is smaller in size so, six
F- ions can surround a Sulphur atom. The case is not so with
chlorine atom due to its large size. So, read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9834In the ring test of ion, ion reduces nitrate ion
to nitric oxide, which combines with (aq) ion to form brown
complex. Write the reactions involved in the formation of brown ring. Answer: read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9835Explain why ozone is thermodynamically
less stable than oxygen? Answer: Ozone is thermodynamically less stable
than oxygen because its decomposition into oxygen results in the liberation
of heat (is negative) and an
increase in entropy (i... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9836Name three oxoacids of nitrogen. Write
the disproportionation reaction of that oxoacid of nitrogen in which nitrogen
is in + 3 oxidation state. Answer: Three oxoacids of nitrogen having
oxidation state +3 are
(a) HNO2 , nitrous acid
(... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9837PCl5 reacts with finely
divided silver on heating and a white silver salt is obtained, which
dissolves on adding excess aqueous NH3 solution. Write the
reactions involved to explain what happens. Answer: PCl5 reacts with finely
divided si... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9838Match the species given in Column I with
the shape given in Column II and mark the correct option.
read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9839Match the items in Column I and Column II
and mark the correct option.
Column I... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9840In the
following question, a statement of assertion is followed by a statement of
reason.
Assertion (A)
HNO3 makes iron passive.
Reason (R) HNO3
forms a protective layer of ferric nitrate on the surface of iron.
... read moreJEE-Main - Grade 12 - Chemistry - The p-Block Elements - Study ref# 9841In the
following question, a statement of assertion is followed by a statement of
reason.
Assertion (A)
SF6 cannot be hydrolysed but SF4 can be.
Reason (R) Six
F-atoms in SF6 prevent the attack of H2O on Sulphur... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9842The electronic configuration of Cu(II) 3d9
where as 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(... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9843On addition of small amount of KMnO4
to concentrated H2SO4, a green oily compound is
obtained which is highly explosive in nature. Identify the compound from the
following.
(a)
(b) ... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9844The magnetic nature of elements depends
on the presence of unpaired electrons. Identify the configuration of
transition element, which shows highest magnetic moment.
Hint: This problem is based on
calculation of magnetic moment can be ... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9845Which of the following oxidation state is
common for all lanthanoids?
(a) +2
(b) +3
(c) +4
(d) +5 Answer: (b) Lanthanoids show common state of +3.
Some of which also show +2 and +4 stable oxidation state alongwith +3
oxidation st... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9846When KMnO4 solution is needed
to oxalic acid solution, the decolourisation is slow the beginning but
becomes instantaneous after some time because
(a) CO2 is formed as the
product
(b) Reaction is exothermic
(c) read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9847There are 14 elements in actinoid series.
Which of the following elements does not belong to this series?
(a) U
(b) Np
(c) Tm
(d) Fm Answer: (c) Tm (Z = 69) do not belong to actinoid
series. The actinoid series is with atomic number... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9848Which of the following is amphoteric
oxide?
(a) ,
(b)
(c) read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9849Interstitial compounds are formed when
small atoms are trapped inside the crystal lattice of metals. Which of the
following is not the characteristics property of interstitial compounds?
(a) They have high melting points in
comparison to ... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9850The magnetic moment is associated with
its spin angular momentum an orbital angular momentum. Spin only magnetic
moment value of Cr3+ ion is
(a) 2.87 BM
(b) 3.87 BM
(c) 3.47 BM
(d) 3.57 BM Answer: (b) The magnetic moment is associat... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9851When acidified solution is
added to salt then changes to
(a) Sn
(b) Sn3+
(c) Sn4+
(d) Sn+ Answer: read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9852Although zirconium belongs to 4d
transition series and hafnium to 5d transition series even then they
show similar physical and chemical properties because……………. .
(a) both belong to d-block
(b) both have some num... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9853Which of the following actinoids show
oxidation states upto +7?
(a) Am
(b) Pu
(c) U
(d) Np Answer: (b, d)
The oxidation states of the following
actinoids are
(a) Americium (Z = 95); Electronic
configuration =
Oxidation... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9854General electronic configuration of
actinoids is
(a) U (Atomic number. 92)
(b) Np (Atomic number. 93)
(c) Pu (Atomic number. 94)
(d) Am (Atomic number. 95) Answer: (a, b)
General electronic configuration of
actinoids is U and
... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9855Which of the following lanthanoids show
+2 oxidation state besides the characteristics oxidation state +3 of
lanthanoids?
(a) Ce
(b) Eu
(c) Yb
(d) Ho Answer: (b, c)
(a) Cerium (Z = 57) Electronic
configuration =
Oxidatio... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9856Why does copper not replace hydrogen from
acids? Answer: Copper not replace hydrogen from acids
because Cu has positive E̊ value, i.e., less reactive than
hydrogen which has electrode potential 0.00V.... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9857Why E- values for Mn, Ni and
Zn are more negative than expected? Answer: Negative values of Mn2+ and Zn2+
are related to stabilities of half-filled and completely filled configuration
respectively. But for Ni2+, E̊ value is related to
... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9858Transition elements show high melting points.
Why? Answer: Transition elements show high melting
points, due to involvement of greater number of electrons in the interatomic
bonding from (n-1)d- orbitals in addition to ns
electrons in fo... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9859Out of and , which is more
stable and why? Answer: Among and, is more stable.
Stability of complex can be explained on the basis of stabilit... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9860When a brown compound of manganese (A) is
treated with HCI it gives a gas (B). The gas taken in excess, reacts with NH3
to give an explosive compound (C). Identify compounds A, B and C. Answer: MnO2 is the brown compound of
Mn which reacts w... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9861Ionisation enthalpies of Ce, Pr and Nd
are higher than Th, Pa and U. Why? Answer: Ce, Pr and Nd are lanthanoids and have
incomplete 4f shell while Th, Pa and U are actinoids and have 5f
shell incomplete.
In the beginning, when 5f-orbitals... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9862Explain why does colour of KMnO4
disappear when oxalic acid is added to its solution in acidic medium? Answer: When oxalic acid is added to acidic
solution of KMnO4, its colour disappear due to reduction of ion to Mn2+.
Chemical reaction oc... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9863When orange solution containing ion is treated
with an alkali, a yellow solution is formed and when H+ ions are
added to yellow solution, an orange solution is obtained. Explain why does
this happen? Answer: When orange solution containing i... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9864 of Cu is +0.34V
while that of Zn is -0.76 V. Explain. Answer: value of Cu is
positive because of the fact that sum of sublimation enthalpy ... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9865The halides of transition elements become
more covalent with increasing oxidation state of the metal. Why? Answer: As the oxidation state increases, size of
the ion of transition element decreases. As per Fajan’s rule, as the size of
metal i... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9866Match the catalysts given in Column I
with the process given in Column II.
Column I
... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9867Match the compounds/elements given in
Column I with uses given in Column II.
Column I
... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9868Match the statements given in Column I
with the oxidation states given in Column II.
... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9869Match the property given in Column I with
the element given in Column II.
Column I
... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9870Identify A to E and also explain the
reaction involved.
Answer: The substances from A to E
A = Cu; B = ; C = ; D = ; E =
Reactions:
(i) read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9871When an oxide of manganese (A) is fused
with KOH in the presence of an oxidizing agent and dissolved in water, it
gives a dark green solution of compound (B). Compound (B) disproportionates
in neutral or acidic solution to give purple compou... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9872(a) Answer the following questions
(i) Which element of the first transition
series has highest second ionization enthalpy?
(ii) Which element of the first
transition series has highest third ionization enthalpy?
(iii) Which element of... read moreJEE-Main - Grade 12 - Chemistry - The d and f block Elements - Study ref# 9873Gadolinium belongs to 4f series.
Its atomic number is 64. Which of the following is the correct electronic
configuration of gadolinium?
(a)
(b) read more
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