Other Chemistry · JEE Main previous year questions

2018 14 questions

1. Q612018 · 16 Apr 2018 · Shift 1

   Which of the following statements is false ?

   1. A.Photon has momentum as well as wavelength.
   2. B.Splitting of spectral lines in electrical field is called Stark effect.
   3. C.Rydberg constant has unit of energy.
   4. D.Frequency of emitted radiation from a black body goes from a lower wavelength to higher wavelength as the temperature increases.
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   Answer: D

2. Q622018 · 16 Apr 2018 · Shift 1

   At 320 K, a gas ${\text{A}}_2$ is 20% dissociated to A(g). The standard free energy change at 320 K and 1 atm in $\text{J}{\text{mol}}^{-1}$ is approximately : ($\text{R}=8.314{\text{JK}}^{-1}{\text{mol}}^{-1}$; $\ln 2=0.693$; $\ln 3=1.098$)

   1. A.4763
   2. B.2068
   3. C.1844
   4. D.4281
   Show answer

   Answer: A

3. Q632018 · 16 Apr 2018 · Shift 1

   The mass of a non-volatile, non-electrolyte solute (molar mass = $50\text{g}{\text{mol}}^{-1}$ ) needed to be dissolved in 114 g octane to reduce its vapour pressure by 75%, is :

   1. A.37.5 g
   2. B.75 g
   3. C.150 g
   4. D.50 g
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   Answer: C

4. Q642018 · 16 Apr 2018 · Shift 1

   The incorrect statement is :

   1. A.${\text{Cu}}^{2+}$ salts give red coloured borax bead test in reducing flame.
   2. B.${\text{Cu}}^{2+}$ and ${\text{Ni}}^{2+}$ ions give black precipitate with ${\text{H}}_2\text{S}$ in presence of HCl solution.
   3. C.Ferric ion gives blood red color with potassium thiocyanate.
   4. D.${\text{Cu}}^{2+}$ ion gives chocolate coloured precipitate with potassium ferrocyanide solution.
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   Answer: B

5. Q652018 · 16 Apr 2018 · Shift 1

   The incorrect geometry is represented by :

   1. A.${\text{BF}}_3$ - trigonal planar
   2. B.${\text{H}}_2\text{O}$ - bent
   3. C.${\text{NF}}_3$ - trigonal planar
   4. D.${\text{AsF}}_5$ - trigonal bipyramidal
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   Answer: C

6. Q702018 · 16 Apr 2018 · Shift 1

   For standardizing NaOH solution, which of the following is used as a primary standard ?

   1. A.Ferrous Ammonium Sulfate
   2. B.dil. HCl
   3. C.Oxalic acid
   4. D.Sodium tetraborate
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   Answer: C

7. Q712018 · 16 Apr 2018 · Shift 1

   Among the following, the incorrect statement is :

   1. A.Maltose and lactose has 1, 4 - glycosidic linkage.
   2. B.Sucrose and amylose has 1, 2 - glycosidic linkage
   3. C.Cellulose and amylose has 1, 4 - glycosidic linkage.
   4. D.Lactose contains $\beta$-D-galactose and $\beta$-D-glucose.
   Show answer

   Answer: B

8. Q752018 · 16 Apr 2018 · Shift 1
   
   1. A.
   2. B.
   3. C.
   4. D.
   Show answer

   Answer: A

9. Q832018 · 16 Apr 2018 · Shift 1

   For which of the following processes, $\Delta \mathrm{S}$ is negative ?

   1. A.${\mathrm{H}}_2(\mathrm{g})\to 2\mathrm{H}(\mathrm{g})$
   2. B.${\mathrm{N}}_2(\mathrm{g},1\mathrm{atm})\to {\mathrm{N}}_2(\mathrm{g},5\mathrm{atm})$
   3. C.$\mathrm{C}(\mathrm{diamond})\to \mathrm{C}(\mathrm{graphite})$
   4. D.${\mathrm{N}}_2(\mathrm{g},273\mathrm{K})\to {\mathrm{N}}_2(\mathrm{g},300\mathrm{K})$
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   Answer: B

10. Q842018 · 16 Apr 2018 · Shift 1

    If 50% of a reaction occurs in 100 second and 75% of the reaction occurs in 200 second, the order of this reaction is :

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

11. Q732018 · 15 Apr 2018 · Shift 1

    The correct combination is :

    1. A.$[\text{Ni}(\text{CN}{)}_4{]}^{2-}$ – tetrahedral ; $[\text{Ni}(\text{CO}{)}_4]$ – paramagnetic
    2. B.$[\text{Ni}(\text{Cl}{)}_4{]}^{2-}$ – paramagnetic ; $[\text{Ni}(\text{CO}{)}_4]$ – tetrahedral
    3. C.$[\text{Ni}(\text{Cl}{)}_4{]}^{2-}$ – square-planar ; $[\text{Ni}(\text{CN}{)}_4{]}^{2-}$ – paramagnetic
    4. D.$[\text{Ni}(\text{Cl}{)}_4{]}^{2-}$ – diamagnetic ; $[\text{Ni}(\text{CO}{)}_4]$ – square-planar
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    Answer: B

12. Q782018 · 15 Apr 2018 · Shift 1
    
    1. A.
    2. B.
    3. C.
    4. D.
    Show answer

    Answer: A

13. Q802018 · 15 Apr 2018 · Shift 1
    
    1. A.(b) < (a) < (c) < (d)
    2. B.(a) < (b) < (c) < (d)
    3. C.(b) < (a) < (d) < (c)
    4. D.(a) < (b) < (d) < (c)
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    Answer: D

14. Q712018 · 8 Apr 2018 · Shift 1

    Which of the following salts is the most basic in aqueous solution?

    1. A.$\text{Pb}({\text{CH}}_3\text{COO}{)}_2$
    2. B.$\text{Al}(\text{CN}{)}_3$
    3. C.${\text{CH}}_3\text{COOK}$
    4. D.${\text{FeCl}}_3$
    Show answer

    Answer: C