Other Chemistry · JEE Main previous year questions

2021 58 questions

1. Q732021 · 26 Feb 2021 · Shift 2
   
   1. A.
   2. B.
   3. C.
   4. D.
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   Answer: D

2. Q802021 · 26 Feb 2021 · Shift 2

   Calgon is used for water treatment. Which of the following statement is NOT true about Calgon?

   1. A.It is also known as Graham's salt.
   2. B.It is polymeric compound and is water soluble.
   3. C.It does not remove $\mathrm{C}{\mathrm{a}}^{2+}$ ion by precipitation.
   4. D.Calgon contains the $2^{\text{nd}}$ most abundant element by weight in the Earth's crust.
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   Answer: D

3. Q852021 · 26 Feb 2021 · Shift 2· Numerical answer

   Emf of the following cell at 298K in V is $x\times 10^{-2}$. $Zn|Z{\mathrm{n}}^{2+}(0.1\mathrm{M})||A{\mathrm{g}}^{+}(0.01\mathrm{M})|Ag$ The value of x is _________. (Rounded off to the nearest integer) [Given : $E_{\mathrm{Z}{\mathrm{n}}^{2+}/Zn}^{\theta }=-0.76\mathrm{V}$; $E_{\mathrm{A}{\mathrm{g}}^{+}/Ag}^{\theta }=+0.80\mathrm{V}$; $\frac{2.303RT}{F}=0.059$]

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   Answer: 147

4. Q892021 · 26 Feb 2021 · Shift 2· Numerical answer

   The $\mathrm{NaN}{\mathrm{O}}_3$ weighed out to make 50 mL of an aqueous solution containing $70.0\mathrm{mg}\mathrm{N}{\mathrm{a}}^{+}$ per mL is _________ g. (Rounded off to the nearest integer) $[\text{Given : Atomic weight in }\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}\text{ - }\mathrm{Na}:23;\mathrm{N}:14;\mathrm{O}:16]$

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   Answer: 13

5. Q662021 · 25 Feb 2021 · Shift 2
   
   1. A.$\text{IV}>\text{III}>\text{II}>\text{I}$
   2. B.$\text{III}>\text{II}>\text{I}>\text{IV}$
   3. C.$\text{II}>\text{III}>\text{IV}>\text{I}$
   4. D.$\text{I}>\text{II}>\text{III}>\text{IV}$
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   Answer: C

6. Q752021 · 25 Feb 2021 · Shift 2

   Water does not produce $\mathrm{CO}$ on reacting with :

   1. A.$\mathrm{C}$
   2. B.$\mathrm{C}{\mathrm{H}}_4$
   3. C.${\mathrm{C}}_3{\mathrm{H}}_8$
   4. D.$\mathrm{C}{\mathrm{O}}_2$
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   Answer: D

7. Q782021 · 25 Feb 2021 · Shift 2

   The major components of German Silver are :

   1. A.Zn, Ni and Ag
   2. B.Cu, Zn and Ni
   3. C.Cu, Zn and Ag
   4. D.Ge, Cu and Ag
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   Answer: B

8. Q802021 · 25 Feb 2021 · Shift 2

   Which one of the following statements is FALSE for hydrophilic sols?

   1. A.They do not require electrolytes for stability.
   2. B.The sols cannot be easily coagulated.
   3. C.These sols are reversible in nature.
   4. D.Their viscosity is of the order of that of ${\mathrm{H}}_2\mathrm{O}$.
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   Answer: D