Other Chemistry · JEE Main previous year questions

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.

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

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

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.

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

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

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.

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

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.${\mathrm{N}}_2(\mathrm{g},273\mathrm{K})\to {\mathrm{N}}_2(\mathrm{g},300\mathrm{K})$

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

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

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

1. A.(b) < (a) < (c) < (d)
2. B.(a) < (b) < (c) < (d)
3. C.(b) < (a) < (d) < (c)
4. D.(a) < (b) < (d) < (c)

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.${\text{FeCl}}_3$

What quantity (in mL) of a 45% acid solution of a mono-protic strong acid must be mixed with a 20% solution of the same acid to produce 800 mL of a 29.875% acid solution ?

1. A.320
2. B.325
3. C.316
4. D.330

To find the standard potential of ${\mathrm{M}}^{3+}/M$ electrode, the following cell is constituted : $Pt/M/{\mathrm{M}}^{3+}(0.001\mathrm{mol}{\mathrm{L}}^{-1})/\mathrm{A}{\mathrm{g}}^{+}(0.01\mathrm{mol}{\mathrm{L}}^{-1})/\mathrm{Ag}$ The emf of the cell is found to be 0.421 volt at 298 K. The standard potential of half reaction ${\mathrm{M}}^{3+}+3{\mathrm{e}}^{-}\to \mathrm{M}$ at 298 K will be : (Given $E_{\mathrm{A}{\mathrm{g}}^{+}/Ag}^o$ at 298 K = 0.80 Volt)

1. A.$0.38\mathrm{Volt}$
2. B.$0.32\mathrm{Volt}$
3. C.$1.28\mathrm{Volt}$
4. D.$0.66\mathrm{Volt}$

Which one of the following is an oxide?

1. A.$\mathrm{K}{\mathrm{O}}_2$
2. B.$\mathrm{Ba}{\mathrm{O}}_2$
3. C.$\mathrm{Si}{\mathrm{O}}_2$
4. D.$\mathrm{Cs}{\mathrm{O}}_2$

The group having triangular planar structures is :

1. A.$\mathrm{B}{\mathrm{F}}_3$, $\mathrm{N}{\mathrm{F}}_3$, $C{O}_3^{2-}$
2. B.$C{O}_3^{2-}$, $N{O}_3^{-}$, $\mathrm{S}{\mathrm{O}}_3$
3. C.$\mathrm{N}{\mathrm{H}}_3$, $\mathrm{S}{\mathrm{O}}_3$, $C{O}_3^{2-}$
4. D.$\mathrm{NC}{\mathrm{l}}_3$, $\mathrm{BC}{\mathrm{l}}_3$, $\mathrm{S}{\mathrm{O}}_3$

Which of the following ions does not liberate hydrogen gas on reaction with dilute acids ?

1. A.$\mathrm{T}{\mathrm{i}}^{2+}$
2. B.${\mathrm{V}}^{2+}$
3. C.$\mathrm{C}{\mathrm{r}}^{2+}$
4. D.$\mathrm{M}{\mathrm{n}}^{2+}$

$[\mathrm{C}{\mathrm{o}}_2(\mathrm{CO}{)}_8]$ displays :

1. A.one Co–Co bond, six terminal CO and two bridging CO
2. B.one Co–Co bond, four terminal CO and four bridging CO
3. C.no Co–Co bond, six terminal CO and two bridging CO
4. D.no Co–Co bond, four terminal CO and four bridging CO

The incorrect statement among the following is :

1. A.$\alpha$-D-glucose and $\beta$-D-glucose are anomers.
2. B.$\alpha$-D-glucose and $\beta$-D-glucose are enantiomers.
3. C.Cellulose is a straight chain polysaccharide made up of only $\beta$-D-glucose units.
4. D.The penta acetate of glucose does not react with hydroxyl amine

The correct sequence of decreasing number of $\pi$-bonds in the structures of ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3$, ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ and ${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7$ is :

1. A.${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3>{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4>{\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7$
2. B.${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4>{\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7>{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3$
3. C.${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7>{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4>{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3$
4. D.${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7>{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3>{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$

For a reaction, $\mathrm{A}(\mathrm{g})\to \mathrm{A}(\mathrm{\ell })$; $\Delta \mathrm{H}=-3\mathrm{RT}$. The correct statement for the reaction is :

1. A.$\Delta \mathrm{H}=\Delta \mathrm{U}\ne 0$
2. B.$\Delta \mathrm{H}=\Delta \mathrm{U}=0$
3. C.$|\Delta \mathrm{H}|<|\Delta \mathrm{U}|$
4. D.$|\Delta \mathrm{H}|>|\Delta \mathrm{U}|$

If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of $\mathrm{H}{\mathrm{e}}^{+}$ is :

1. A.$\frac{5A}{9}$
2. B.$\frac{9A}{5}$
3. C.$\frac{36A}{5}$
4. D.$\frac{36A}{7}$

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