p-Block Elements · JEE Main previous year questions

Total number of ions from the following with noble gas configuration is _______. ${\text{Sr}}^{2+}(z=38),{\text{Cs}}^{+}(z=55),{\text{La}}^{2+}(z=57),{\text{Pb}}^{2+}(z=82),{\text{Yb}}^{2+}(z=70)$ and ${\text{Fe}}^{2+}(z=26)$

The radical which mainly causes ozone depletion in the presence of UV radiations is :

1. A.${\mathrm{NO}}^{\cdot }$
2. B.$\dot{\mathrm{C}}{\mathrm{H}}_3$
3. C.$\dot{\mathrm{C}}\mathrm{l}$
4. D.$\dot{\mathrm{O}}\mathrm{H}$

The correct group of halide ions which can be oxidised by oxygen in acidic medium is :

1. A.${\mathrm{Br}}^{-}$ only
2. B.${\mathrm{Cl}}^{-},{\mathrm{Br}}^{-}$ and ${\mathrm{I}}^{-}$ only
3. C.${\mathrm{Br}}^{-}$ and ${\mathrm{I}}^{-}$ only
4. D.${\mathrm{I}}^{-}$ only

Which of the following are the Green house gases? A. Water vapour B. Ozone C. ${\mathrm{I}}_2$ D. Molecular hydrogen Choose the most appropriate answer from the options given below :

1. A.A and D only
2. B.A and B only
3. C.B and C only
4. D.C and D only

If the formula of Borax is $\mathrm{N}{\mathrm{a}}_2{\mathrm{B}}_4{\mathrm{O}}_{\mathrm{x}}(\mathrm{OH}{)}_{\mathrm{y}}\cdot \mathrm{z}{\mathrm{H}}_2\mathrm{O}$, then $x+y+z=$ ____

Given below are two statements : Statement I : $\mathrm{SbC}{\mathrm{l}}_5$ is more covalent than $\mathrm{SbC}{\mathrm{l}}_3$ Statement II: The higher oxides of halogens also tend to be more stable than the lower ones. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A.Both statement I and Statement II are correct
2. B.Both Statement I and Statement II are incorrect
3. C.Statement I is correct but Statement II is incorrect
4. D.Statement I is incorrect but Statement II is correct

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : A solution of the product obtained by heating a mole of glycine with a mole of chlorine in presence of red phosphorus generates chiral carbon atom. Reason R : A molecule with 2 chiral carbons is always optically active. In the light of the above statements, choose the correct answer from the options given below:

1. A.Both A and R are true and R is the correct explanation of A
2. B.Both A and R are true but R is NOT the correct explanation of A
3. C.A is true but R is false
4. D.A is false but R is true

In the following reactions, the total number of oxygen atoms in X and Y is _________. ${\text{Na}}_2\text{O}+{\text{H}}_2\text{O}\to 2\text{X}$ ${\text{Cl}}_2{\text{O}}_7+{\text{H}}_2\text{O}\to 2\text{Y}$

Which halogen is known to cause the reaction given below : $2{\mathrm{Cu}}^{2+}+4{\mathrm{X}}^{-}\to \mathrm{C}{\mathrm{u}}_2{\mathrm{X}}_2(\mathrm{s})+{\mathrm{X}}_2$

1. A.All halogens
2. B.Only Iodine
3. C.Only Bromine
4. D.Only Chlorine

1. A.$\mathrm{A}-\mathrm{B}{\mathrm{r}}_{(\mathrm{b})};\mathrm{B}-{\mathrm{I}}_{(\mathrm{a})};\mathrm{C}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})};\mathrm{D}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})}$
2. B.$\mathrm{A}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})};\mathrm{B}-{\mathrm{I}}_{(\mathrm{a})};\mathrm{C}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})};\mathrm{D}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})}$
3. C.$\mathrm{A}-\mathrm{B}{\mathrm{r}}_{(\mathrm{b})};\mathrm{B}-{\mathrm{I}}_{(\mathrm{b})};\mathrm{C}-\mathrm{B}{\mathrm{r}}_{(\mathrm{b})};\mathrm{D}-\mathrm{B}{\mathrm{r}}_{(\mathrm{b})}$
4. D.$\mathrm{A}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})};\mathrm{B}-{\mathrm{I}}_{(\mathrm{a})};\mathrm{C}-\mathrm{B}{\mathrm{r}}_{(\mathrm{b})};\mathrm{D}-\mathrm{B}{\mathrm{r}}_{(\mathrm{a})}$

$\mathrm{Xe}{\mathrm{F}}_4$ reacts with $\mathrm{Sb}{\mathrm{F}}_5$ to form $[{\mathrm{XeF}}_m{]}^{n+}[{\mathrm{SbF}}_y{]}^{z-}$. $\mathrm{m}+\mathrm{n}+\mathrm{y}+\mathrm{z}=$ ___________

Which of these reactions is not a part of breakdown of ozone in stratosphere?

1. A.$\mathrm{C}{\mathrm{F}}_2\mathrm{C}{\mathrm{l}}_2(\mathrm{g})\stackrel{\mathrm{uv}}{\to }\dot{\mathrm{C}}\mathrm{l}(\mathrm{g})+\dot{\mathrm{C}}{\mathrm{F}}_2\mathrm{Cl}(\mathrm{g})$
2. B.$\dot{\mathrm{C}}\mathrm{l}(\mathrm{g})+{\mathrm{O}}_3(\mathrm{g})⟶\mathrm{Cl}\dot{\mathrm{O}}(\mathrm{g})+{\mathrm{O}}_2(\mathrm{g})$
3. C.$2Cl\dot{\mathrm{O}}⟶\mathrm{Cl}{\mathrm{O}}_2(\mathrm{g})+\dot{\mathrm{C}}\mathrm{l}(\mathrm{g})$
4. D.$\mathrm{Cl}\dot{\mathrm{O}}(\mathrm{g})+\mathrm{O}(\mathrm{g})⟶\dot{\mathrm{C}}\mathrm{l}(\mathrm{g})+{\mathrm{O}}_2(\mathrm{g})$

Match List I with List II | LIST I (Element detected) | LIST II (Reagent used / Product formed) | | :--- | :--- | | A. Nitrogen | I. ${\text{Na}}_2[\text{Fe}(\text{CN}{)}_5\text{NO}]$ | | B. Sulphur | II. ${\text{AgNO}}_3$ | | C. Phosphorous | III. ${\text{Fe}}_4[\text{Fe}(\text{CN}{)}_6{]}_3$ | | D. Halogen | IV. $({\text{NH}}_4{)}_2{\text{MoO}}_4$ | Choose the correct answer from the options given below:

1. A.A-III, B-I, C-IV, D-II
2. B.A-II, B-I, C-IV, D-III
3. C.A-IV, B-II, C-I, D-III
4. D.A-II, B-IV, C-I, D-III

Given below are two statements: Statement I : Chlorine can easily combine with oxygen to form oxides; and the product has a tendency to explode. Statement II : Chemical reactivity of an element can be determined by its reaction with oxygen and halogens. In the light of the above statements, choose the correct answer from the options given below :

1. A.Statement I is true but Statement II is false
2. B.Both the Statements I and II are false
3. C.Statement I is false but Statement II is true
4. D.Both the Statements I and II are true

For reaction : ${\mathrm{SO}}_2(\text{ g})+\frac{1}{2}{\mathrm{O}}_2(\text{ g})\rightleftharpoons {\mathrm{SO}}_3(\text{ g})$ ${\mathrm{K}}_{\mathrm{p}}=2\times 10^{12}$ at $27^{\circ }\text{C}$ and $1\text{ atm}$ pressure. The ${\mathrm{K}}_{\mathrm{c}}$ for the same reaction is ___________ $\times 10^{13}$. (Nearest integer) (Given $\mathrm{R}=0.082{\text{ L atm K}}^{-1}{\text{ mol}}^{-1}$)

In the following halogenated organic compounds, the one with the maximum number of chlorine atoms in its structure is :

1. A.Gammaxene
2. B.Chloropicrin
3. C.Chloral
4. D.Freon-12

Assume carbon burns according to the following equation : $2{\mathrm{C}}_{(\mathrm{s})}+{\mathrm{O}}_{2(\mathrm{g})}\to 2\mathrm{CO}(\mathrm{g})$ when $12\text{ g}$ carbon is burnt in $48\text{ g}$ of oxygen, the volume of carbon monoxide produced is ___________ $\times 10^{-1}\text{ L}$ at STP [nearest integer] [Given: Assume CO as ideal gas, Mass of C is $12{\text{ g mol}}^{-1}$, Mass of O is $16{\text{ g mol}}^{-1}$ and molar volume of an ideal gas at STP is $22.7{\text{ L mol}}^{-1}$ ]

Amongst the following, the number of species having the linear shape is ___________. ${\mathrm{XeF}}_2,{\mathrm{I}}_3^{+},{\mathrm{C}}_3{\mathrm{O}}_2,{\mathrm{I}}_3^{-},{\mathrm{CO}}_2,{\mathrm{SO}}_2,{\mathrm{BeCl}}_2\text{ and }{\mathrm{BCl}}_2^{\ominus }$

During the qualitative analysis of ${\mathrm{SO}}_3^{2-}$ using dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$, ${\mathrm{SO}}_2$ gas is evolved which turns ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution (acidified with dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$) :

1. A.blue
2. B.black
3. C.red
4. D.green

Compound that will give positive Lassaigne's test for both nitrogen and halogen is :

1. A.$\mathrm{N}{\mathrm{H}}_{2}OH.HCl$
2. B.${\mathrm{N}}_2{\mathrm{H}}_4.HCl$
3. C.$\mathrm{C}{\mathrm{H}}_3\mathrm{N}{\mathrm{H}}_2.HCl$
4. D.$\mathrm{N}{\mathrm{H}}_4\mathrm{Cl}$

Total number of acidic oxides among ${\mathrm{N}}_2{\mathrm{O}}_3,\mathrm{N}{\mathrm{O}}_2,{\mathrm{N}}_2\mathrm{O},\mathrm{C}{\mathrm{l}}_2{\mathrm{O}}_7,\mathrm{S}{\mathrm{O}}_2,\mathrm{CO},\mathrm{CaO},\mathrm{N}{\mathrm{a}}_2\mathrm{O}$ and $\mathrm{NO}$ is ____.

In sulphur estimation, 0.471 g of an organic compound gave 1.4439 g of barium sulphate. The percentage of sulphur in the compound is ____________ (Nearest Integer) (Given : Atomic mass Ba: 137 u, S: 32 u, O: 16 u)

The total number of lone pairs of electrons on oxygen atoms of ozone is __________.

A. Ammonium salts produce haze in atmosphere. B. Ozone gets produced when atmospheric oxygen reacts with chlorine radicals. C. Polychlorinated biphenyls act as cleansing solvents. D. 'Blue baby' syndrome occurs due to the presence of excess of sulphate ions in water. Choose the correct answer from the options given below :

1. A.B and C only
2. B.A and D only
3. C.A, B and C only
4. D.A and C only

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R Assertion A : Butylated hydroxy anisole when added to butter increases its shelf life. Reason R : Butylated hydroxy anisole is more reactive towards oxygen than food. In the light of the above statements, choose the most appropriate answer from the options given below

1. A.A is correct but R is not correct
2. B.Both A and R are correct but R is NOT the correct explanation of A
3. C.Both A and R are correct and R is the correct explanation of A
4. D.A is not correct but R is correct