Hydrogen & s-Block · JEE Main previous year questions

2019 10 questions

1. Q772019 · 12 Apr 2019 · Shift 2

   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
   Show answer

   Answer: A

2. Q892019 · 10 Apr 2019 · Shift 2

   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
   Show answer

   Answer: A

3. Q872019 · 9 Apr 2019 · Shift 2

   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
   Show answer

   Answer: C

4. Q702019 · 8 Apr 2019 · Shift 2

   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.$\mathrm{Be}{\mathrm{X}}_2$
   Show answer

   Answer: D

5. Q692019 · 12 Jan 2019 · Shift 1

   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
   Show answer

   Answer: B

6. Q892019 · 12 Jan 2019 · Shift 2

   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 $\mathrm{Cl}{\mathrm{O}}_3^{-}$
   Show answer

   Answer: D

7. Q672019 · 11 Jan 2019 · Shift 2

   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
   Show answer

   Answer: C

8. Q772019 · 11 Jan 2019 · Shift 2
   
   1. A.
   2. B.
   3. C.
   4. D.
   Show answer

   Answer: B, C

9. Q832019 · 11 Jan 2019 · Shift 2

   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)
   Show answer

   Answer: D

10. Q882019 · 11 Jan 2019 · Shift 2

    The hydride that is NOT electron deficient :

    1. A.${\mathrm{B}}_2{\mathrm{H}}_6$
    2. B.$\mathrm{Al}{\mathrm{H}}_3$
    3. C.$\mathrm{Ga}{\mathrm{H}}_3$
    4. D.$\mathrm{Si}{\mathrm{H}}_4$
    Show answer

    Answer: D