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#### Mischmetal is an alloy consisting mainly of :Option: 1 lanthanoid metalsOption: 2 actionoid and transition metalsOption: 3 Lanthanoid and actionoid metalsOption: 4 actionoid metals

Mischmetal is an alloy of lanthanoid metals with Fe.

It consists of a lanthanoid metal (~95%) and iron (~5%) and traces of S, C, Ca, and Al.

Therefore, the correct option is (1).

#### The incorrect statement(s) among (a)-(c) is (are): (a) W(VI) is more stable than Cr(VI) (b) in the presence of HCl, permaganate titrations provide satisfactory results. (c) some lanthnoid oxides can be used as phosphorousOption: 1 (b) and (c) onlyOption: 2 (a) and (b) onlyOption: 3 (b) onlyOption: 4 (a) only

(a) W(VI) is more stable than Cr(VI). It is true and given in NCERT.

(b) in the presence of HCl permanganate titrations provide satisfactory results. It is incorrect.

Permanganate titrations in presence of hydrochloric acid are unsatisfactory since hydrochloric acid is oxidised to chlorine.

(c) Some individual Ln oxides are used as phosphors in television screens and similar fluorescing surfaces.

So,(b) is incorrect.

Therefore, the correct option is (3).

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#### The reaction white phosphorus on boiling with alkali in inert atmosphere resulted inthe formation of product 'A'. The reaction of 1 mol of 'A' with excess of in aqueous medium gives ________mol (s) of . (Round off to the Nearest Integer).Option: 1 4Option: 2 -Option: 3 -Option: 4 -

The reaction of white phosphorus on boiling with alkali in the inert atmosphere resulted in the formation of the product 'A'.

$\mathrm{P}_{4}+3 \mathrm{OH}^{-}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{PH}_{3}+\underset{\text { (A) }}{3 \mathrm{H}_{2} \mathrm{PO}_{2}^{-}}$

The reaction 1 mol of 'A' with an excess of AgNO3 in an aqueous medium gives 4 moles of Ag.

$\underset{1 \text { mole }}{\mathrm{H}_{2} \mathrm{PO}_{2}^{-}}+\underset{\text { excess }}{4 \mathrm{Ag}^{+}}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow \underset{4 \text { mole }}{4 \mathrm{Ag}\ +\ } \mathrm{H}_{3} \mathrm{PO}_{4}+3 \mathrm{H}^{+}$

Ans = 4

#### One of the by-products formed during the recovery of NH3 from Solvay process is :Option: 1 NaHCO3Option: 2 CaCl2Option: 3 Ca(OH)2Option: 4 NH4Cl

On a small scale ammonia is obtained from ammonium salts which decompose when treated with caustic soda or calcium hydroxide.

$2 \mathrm{NH}_{4} \mathrm{Cl}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow 2 \mathrm{NH}_{3}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{CaCl}_{2}$

$\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}+2 \mathrm{NaOH} \rightarrow 2 \mathrm{NH}_{3}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{Na}_{2} \mathrm{SO}_{4}$

Recovery of NH3

Therefore, the Correct option is (2)

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#### The set of elements that differ in mutual relationship from those of the other sets is :Option: 1 B – SiOption: 2 Li – MgOption: 3 Be – AlOption: 4 Li – Na

Mutual relationships can be anything.

Li–Mg, B–Si, Be–Al show diagonal relationship but Li and Na do not show diagonal relationship as both belongs to the same group and not placed diagonally.

Therefore, the Correct option is (4)

#### Given below are two statements : Statement I : The  value for is Statement II :  is more stable in  state than  state. In the light of the above statements, choose the most appropriate answer from the options given below :   Option: 1 Both statement I and statement II are correct Option: 2 Both statement I and statement II are incorrect Option: 3 Statement I is incorrect but statement II is correct   Option: 4 Statement I is correct but statement II is incorrect

The Eo value for Ce4+/Ce3+ is +1.74 V because the most stable oxidation state of lanthanide series elements is +3.

It means Ce3+ is more stable than Ce4+

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#### A group 15 element, which is a metal and forms a hydride with strongest reducing power among group 15 hydrides. The element is :   Option: 1 Bi Option: 2 As Option: 3 Sb Option: 4 P

N, P are Non-Metal

As, Sb are Metalloid

Bi is Metal

Hydrides of group 15 elements are

NH3 , PH3 , AsH3 , SbH3 , BiH3

In NH3, the hydrogen atom gets a partial positive charge due to less electronegativity. But in BiH3, the hydrogen atom gets a partial negative charge because hydrogen is more electronegative than bismuth.

BiH3 is a strong reducing agent than others because we know that H- is a strong reducing agent and Bi – H bond dissociation energy is very less.

#### Given below are two statements : Statement I : Both CaCl2.6H2O and MgCl2.8H2O  undergo dehydrationon heating. Statement II : BeO is amphoteric whereas the oxides of other elements in the same group are acidic. In the light of the above statements, choose the correct answer from the options given below : Option: 1 Statement I is false but statement II is true Option: 2 Both statement I and Statement II are false Option: 3 Statement I is true but statement II is false   Option: 4 Both statement I and Statement II are true

$\text { (a) } \mathrm{CaCl}_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O} \stackrel{\Delta}{\longrightarrow} \underset{\text { (Anhydrous) }}{\mathrm{CaCl}_{2}}+6 \mathrm{H}_{2} \mathrm{O}$

$\text { (b) } \mathrm{MgCl}_{2} .8 \mathrm{H}_{2} \mathrm{O} \stackrel{\Delta}{\longrightarrow} \mathrm{MgO}+2 \mathrm{HCl}+6 \mathrm{H}_{2} \mathrm{O}$

The dehydration of hydrated chloride of calcium can be achieved. The corresponding hydrated chloride of magnesium on heating suffer hydrolysis.

$\text { (c) } \mathrm{BeO} \rightarrow \text { Amphoteric }$

MgO, CaO, SrO, BaO All are basic oxides.

So, Both Statement I and Statement II are false

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#### Assertaion and Reasoning question: (i) Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A). (ii) Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A). (iii) Assertion (A) is correct, but Reason (R) is incorrect statement. (iv) Assertion (A) is incorrect, but Reason (R) is correct statement.  Assertion (A) : F – F bond in F2 molecule is weak. Reason (R) : F atom is small in size

(ii) Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A).

#### The image distance from the eye lens in the normal eye when we increase the distance of an object from the eye Option: 1 increases. Option: 2 decreases. Option: 3 remains unchanged. Option: 4 depends on the size of the eyeball.

The image distance from the eye lens in the normal eye when we increase the distance of an object from the eye remains unchanged.