Hydrogen & s-Block · JEE Main previous year questions

A source of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, $x\times 10^{20}$ electrons are ejected per second. Assume that wavelength 400 nm is sufficient for ejection of electron from the surface of sodium metal. The value of x is ____. (Nearest integer) (h = $6.626\times 10^{-34}$ Js)

Which one of the following metals forms interstitial hydride easily?

1. A.Cr
2. B.Fe
3. C.Mn
4. D.Co

[structure: Maleic anhydride (five-membered cyclic anhydride with C=C)] Maleic anhydride can prepared by :

1. A.Heating trans-but-2-enedioic acid
2. B.Heating cis-but-2-enedioic acid
3. C.Treating cis-but-2-enedioic acid with alcohol and acid
4. D.Treating trans-but-2-enedioic acid with alcohol and acid

When silver nitrate solution is added to potassium iodide solution then the sol produced is :

1. A.$AgI/{\mathrm{I}}^{-}$
2. B.$AgI/A{\mathrm{g}}^{+}$
3. C.$KI/N{\mathrm{O}}_3^{-}$
4. D.$\mathrm{AgN}{\mathrm{O}}_3/N{\mathrm{O}}_3^{-}$

Match List - I with List - II $$\begin{array}{llll}& \text{List - I}& & \text{List - II}\\ \text{(a)}& \mathrm{Ca}(\mathrm{OCl}{)}_2& \text{(i)}& \text{Antacid}\\ \text{(b)}& \mathrm{CaS}{\mathrm{O}}_4\cdot \frac{1}{2}{\mathrm{H}}_2\mathrm{O}& \text{(ii)}& \text{Cement}\\ \text{(c)}& \mathrm{CaO}& \text{(iii)}& \text{Bleach}\\ \text{(d)}& \mathrm{CaC}{\mathrm{O}}_3& \text{(iv)}& \text{Plaster of paris}\end{array}$$ Choose the most appropriate answer from the options given below :

1. A.(a) - (i), (b) - (iv), (c) - (iii), (d) - (ii)
2. B.(a) - (iii), (b) - (ii), (c) - (iv), (d) - (i)
3. C.(a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)
4. D.(a) - (iii), (b) - (ii), (c) - (i), (d) - (iv)

Match List - I with List - II. | List - I | List - II | | :--- | :--- | | (a) Sodium Carbonate | (i) Deacon | | (b) Titanium | (ii) Castner-Kellner | | (c) Chlorine | (iii) van-Arkel | | (d) Sodium hydroxide | (iv) Solvay | Choose the correct answer from the options given below :

1. A.(a) $\to$ (iv), (b) $\to$ (iii), (c) $\to$ (i), (d) $\to$ (ii)
2. B.(a) $\to$ (iv), (b) $\to$ (i), (c) $\to$ (ii), (d) $\to$ (iii)
3. C.(a) $\to$ (iii), (b) $\to$ (ii), (c) $\to$ (i), (d) $\to$ (iv)
4. D.(a) $\to$ (i), (b) $\to$ (iii), (c) $\to$ (iv), (d) $\to$ (ii)

Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?

1. A.Nitric acid
2. B.Sodium hydroxide
3. C.Ammonia
4. D.Hydrochloric acid

Among the sulphates of alkaline earth metals, the solubilities of $\mathrm{BeS}{\mathrm{O}}_4$ and $\mathrm{MgS}{\mathrm{O}}_4$ in water, respectively, are :

1. A.poor and poor
2. B.poor and high
3. C.high and poor
4. D.high and high

Match the following compounds (Column-I) with their uses (Column-II) : | S.No. | Column-I | S.No. | Column-II | | :--- | :--- | :--- | :--- | | (I) | $\mathrm{Ca}(\mathrm{OH}{)}_2$ | (A) | casts of statues | | (II) | $\mathrm{NaCl}$ | (B) | white wash | | (III) | $\mathrm{CaS}{\mathrm{O}}_4\cdot \frac{1}{2}{\mathrm{H}}_2\mathrm{O}$ | (C) | antacid | | (IV) | $\mathrm{CaC}{\mathrm{O}}_3$ | (D) | washing soda preparation |

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

1. A.(b) only
2. B.(b) and (d)
3. C.(c) and (d)
4. D.(d) only

A chemist has 4 samples of artificial sweetener A, B, C and D. To identify these samples, he performed certain experiments and noted the following observations : (i) A and D both form blue-violet colour with ninhydrin. (ii) Lassaigne extract of C gives positive $\mathrm{AgN}{\mathrm{O}}_3$ test and negative $\mathrm{F}{\mathrm{e}}_4[\mathrm{Fe}(\mathrm{CN}{)}_6{]}_3$ test. (iii) Lassaigne extract of B and D gives positive sodium nitroprusside test Based on these observations which option is correct ?

1. A.A : Aspartame ; B : Alitame ; C : Saccharin ; D : Sucralose
2. B.A : Alitame ; B : Saccharin ; C : Aspartame ; D : Sucralose
3. C.A : Aspartame ; B : Saccharin ; C : Sucralose ; D : Alitame
4. D.A : Saccharin ; B : Alitame ; C : Sucralose ; D : Aspartame

5 g of zinc is treated separately with an excess of (a) dilute hydrochloric acid and (b) aqueous sodium hydroxide. The ratio of the volumes of ${\mathrm{H}}_2$ evolved in these two reactions is :

1. A.1 : 2
2. B.1 : 1
3. C.1 : 4
4. D.2 : 1

Among the statements (a)-(d) the correct ones are : (a) Lithium has the highest hydration enthalpy among the alkali metals. (b) Lithium chloride is insoluble in pyridine. (c) Lithium cannot form ethynide upon its reaction with ethyne. (d) Both lithium and magnesium react slowly with ${\mathrm{H}}_2\mathrm{O}$.

1. A.(b) and (c) only
2. B.(a) and (d) only
3. C.(a), (b) and (d) only
4. D.(a), (c) and (d) only

When gypsum is heated to 393 K, it forms :

1. A.$\mathrm{CaS}{\mathrm{O}}_4\cdot 0.5{\mathrm{H}}_2\mathrm{O}$
2. B.$\mathrm{CaS}{\mathrm{O}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$
3. C.Dead burnt plaster
4. D.Anhydrous $\mathrm{CaS}{\mathrm{O}}_4$

The ammonia ($\mathrm{N}{\mathrm{H}}_3$) released on quantitative reaction of 0.6 g urea ($\mathrm{N}{\mathrm{H}}_2\mathrm{CON}{\mathrm{H}}_2$) with sodium hydroxide ($\mathrm{NaOH}$) can be neutralized by :

1. A.200 ml of 0.02 N HCl
2. B.100 ml of 0.2 N HCl
3. C.100 ml of 0.1 N HCl
4. D.200 ml of 0.4 N HCl

Among the statements (a) - (d), the correct ones are : (a) Decomposition of hydrogen peroxide gives dioxygen. (b) Like hydrogen peroxide, compounds, such as $\mathrm{KCl}{\mathrm{O}}_3$, $\mathrm{Pb}(\mathrm{N}{\mathrm{O}}_3{)}_2$ and $\mathrm{NaN}{\mathrm{O}}_3$ when heated liberate dioxygen. (c) 2-Ethylanthraquinone is useful for the industrial preparation of hydrogen peroxide. (d) Hydrogen peroxide is used for the manufacture of sodium perborate.

1. A.(a), (b), (c) and (d)
2. B.(a) and (c) only
3. C.(a), (b) and (c) only
4. D.(a), (c) and (d) only

In comparison to boron, beryllium has :

1. A.lesser nuclear charge and greater first ionisation enthalpy
2. B.greater nuclear charge and greater first ionisation enthalpy
3. C.greater nuclear charge and lesser first ionisation enthalpy
4. D.lesser nuclear charge and lesser first ionisation enthalpy

The correct statements among (a) to (d) are : (a) saline hydrides produce ${\mathrm{H}}_2$ gas when reacted with ${\mathrm{H}}_2\mathrm{O}$. (b) reaction of $\mathrm{LiAl}{\mathrm{H}}_4$ with $\mathrm{B}{\mathrm{F}}_3$ leads to ${\mathrm{B}}_2{\mathrm{H}}_6$. (c) $\mathrm{P}{\mathrm{H}}_3$ and $\mathrm{C}{\mathrm{H}}_4$ are electron - rich and electron - precise hydrides, respectively. (d) $\mathrm{HF}$ and $\mathrm{C}{\mathrm{H}}_4$ are called as molecular hydrides.

1. A.(a), (b), (c) and (d)
2. B.(a), (c) and (d) only
3. C.(c) and (d) only
4. D.(a), (b) and (c) only

The structures of beryllium chloride in the solid state and vapour, phase, respectively,are :

1. A.chain and chain
2. B.dimeric and chain
3. C.chain and dimeric
4. D.dimeric and dimeric

The covalent alkaline earth metal halide (X = Cl, Br, I) is :

1. A.$\mathrm{Ca}{\mathrm{X}}_2$
2. B.$\mathrm{Sr}{\mathrm{X}}_2$
3. C.$\mathrm{Mg}{\mathrm{X}}_2$
4. D.$\mathrm{Be}{\mathrm{X}}_2$

50 mL of 0.5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. The amount of NaOH in 50 mL of the given sodium hydroxide solution is -

1. A.20 g
2. B.4 g
3. C.80 g
4. D.10 g

Chlorine on reaction with hot and concentrated sodium hydroxide give :

1. A.$\mathrm{Cl}{\mathrm{O}}_3^{-}$ and $\mathrm{Cl}{\mathrm{O}}_2^{-}$
2. B.$\mathrm{C}{\mathrm{l}}^{-}$ and $\mathrm{Cl}{\mathrm{O}}^{-}$
3. C.$\mathrm{C}{\mathrm{l}}^{-}$ and $\mathrm{Cl}{\mathrm{O}}_2^{-}$
4. D.$\mathrm{C}{\mathrm{l}}^{-}$ and $\mathrm{Cl}{\mathrm{O}}_3^{-}$

25 ml of the given HCl solution requires 30 mL of 0.1 M sodium carbonate solution. What is the volume of this HCl solution required to titrate 30 mL of 0.2 M aqueous NaOH solutions ?

1. A.50 mL
2. B.12.5 mL
3. C.25 mL
4. D.75 mL

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

Match the following items in column I with the corresponding items in column II. $$\begin{array}{llll}\text{Item I}& & \text{Item II}& \\ \text{(i)}& \mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3\cdot 10{\mathrm{H}}_2\mathrm{O}& \text{(A)}& \text{Portland cement ingredient}\\ \text{(ii)}& \mathrm{Mg}(\mathrm{HC}{\mathrm{O}}_3{)}_2& \text{(B)}& \text{Castner-Kellner process}\\ \text{(iii)}& \mathrm{NaOH}& \text{(C)}& \text{Solvay process}\\ \text{(iv)}& \mathrm{C}{\mathrm{a}}_3\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_6& \text{(D)}& \text{Temporary hardness}\end{array}$$

1. A.(i)$\to$(D); (ii)$\to$(A); (iii)$\to$(B); (iv)$\to$(C)
2. B.(i)$\to$(B); (ii)$\to$(C); (iii)$\to$(A); (iv)$\to$(D)
3. C.(i)$\to$(C); (ii)$\to$(B); (iii)$\to$(D); (iv)$\to$(A)
4. D.(i)$\to$(C); (ii)$\to$(D); (iii)$\to$(B); (iv)$\to$(A)