Q30. Radius of a certain orbit of hydrogen atom is $8.48 \tilde { A } \ldots$. If energy of electron in this orbit is $E / x$. then $x =$ $\_\_\_\_$ (Given $\mathrm { a } _ { 0 } = 0.529 \tilde { A } \ldots , E =$ energy of electron in ground state).

Q30. In Franck-Hertz experiment, the first dip in the current-voltage graph for hydrogen is observed at 10.2 V . The wavelength of light emitted by hydrogen atom when excited to the first excitation level is $\_\_\_\_$ nm . (Given $\mathrm { hc } = 1245 \mathrm { eVnm } , \mathrm { e } = 1.6 \times 10 ^ { - 19 } \mathrm { C }$ ).

Q30. In an alpha particle scattering experiment distance of closest approach for the $\alpha$ particle is $4.5 \times 10 ^ { - 14 } \mathrm {~m}$. If target nucleus has atomic number 80 , then maximum velocity of $\alpha$ - particle is $\_\_\_\_$ $\times 10 ^ { 5 } \mathrm {~m} / \mathrm { s }$ approximately. $\left( \frac { 1 } { 4 \pi \epsilon _ { 0 } } = 9 \times 10 ^ { 9 } \right.$ SI unit, mass of $\alpha$ particle $\left. = 6.72 \times 10 ^ { - 27 } \mathrm {~kg} \right)$

Q30. A potential divider circuit is connected with a dc source of 20 V , a light emitting diode of glow in voltage 1.8 V and a zener diode of breakdown voltage of 3.2 V . The length (PR) of the resistive wire is 20 cm . The [Figure] minimum length of PQ to just glow the LED is $\_\_\_\_$ cm

Q30. A star has $100 \%$ helium composition. It starts to convert three ${ } ^ { 4 } \mathrm { He }$ into one ${ } ^ { 12 } \mathrm { C }$ via triple alpha process as ${ } ^ { 4 } \mathrm { He } + { } ^ { 4 } \mathrm { He } + { } ^ { 4 } \mathrm { He } \rightarrow { } ^ { 12 } \mathrm { C } + \mathrm { Q }$. The mass of the star is $2.0 \times 10 ^ { 32 } \mathrm {~kg}$ and it generates energy at the rate of $5.808 \times 10 ^ { 30 } \mathrm {~W}$. The rate of converting these ${ } ^ { 4 } \mathrm { He }$ to ${ } ^ { 12 } \mathrm { C }$ is $\mathrm { n } \times 10 ^ { 42 } \mathrm {~s} ^ { - 1 }$, where n is $\_\_\_\_$ [ Take, mass of ${ } ^ { 4 } \mathrm { He } = 4.0026 \mathrm { u }$, mass of ${ } ^ { 12 } \mathrm { C } = 12 \mathrm { u }$ ]

Q30. Monochromatic light of wavelength 500 nm is used in Young's double slit experiment. An interference pattern is obtained on a screen. When one of the slits is covered with a very thin glass plate (refractive index $= 1.5$ ), the central maximum is shifted to a position previously occupied by the $4 ^ { \text {th } }$ bright fringe. The thickness of the glass-plate is $\_\_\_\_$ $\mu \mathrm { m }$.

Q31. Number of elements from the following that CANNOT form compounds with valencies which match with their respective group valencies is $\_\_\_\_$ . B, C, N, S, O, F, P, Al, Si
(1) 7
(2) 3
(3) 5
(4) 6

Q31. Choose the Incorrect Statement about Dalton's Atomic Theory
(1) chemical reactions involve reorganization of
(2) Matter consists of indivisible atoms. atoms
(3) Compounds are formed when atoms of different
(4) Compounds are formed when atoms of different elements combine in any ratio. elements combine in any ratio. All the atoms of a given element have identical properties including identical mass.

Q31. An organic compound has $42.1 \%$ carbon, $6.4 \%$ hydrogen and remainder is oxygen. If its molecular weight is 342, then its molecular formula is :
(1) $\mathrm { C } _ { 11 } \mathrm { H } _ { 18 } \mathrm { O } _ { 12 }$
(2) $\mathrm { C } _ { 12 } \mathrm { H } _ { 20 } \mathrm { O } _ { 12 }$
(3) $\mathrm { C } _ { 12 } \mathrm { H } _ { 22 } \mathrm { O } _ { 11 }$
(4) $\mathrm { C } _ { 14 } \mathrm { H } _ { 20 } \mathrm { O } _ { 10 }$

Q31. The number of moles of methane required to produce $11 \mathrm { gCO } _ { 2 } ( \mathrm {~g} )$ after complete combustion is : (Given molar mass of methane in $\mathrm { gmol } ^ { - 1 } : 16$ )
(1) 0.35
(2) 0.5
(3) 0.75
(4) 0.25

Q31. The density of ' $x$ ' M solution (' $X$ ' molar) of NaOH is $1.12 \mathrm {~g} \mathrm {~mL} ^ { - 1 }$, while in molality, the concentration of the solution is 3 m (3molal). Then $x$ is (Given : Molar mass of NaOH is $40 \mathrm {~g} / \mathrm { mol }$ )
(1) 3.5
(2) 3.8
(3) 2.8
(4) 3.0

Q31. Molality ( m ) of 3 M aqueous solution of NaCl is : (Given : Density of solution $= 1.25 \mathrm {~g} \mathrm {~mL} ^ { - 1 }$, Molar mass in $\mathrm { gmol } ^ { - 1 } : \mathrm { Na } - 23 , \mathrm { Cl } - 35.5$ )
(1) 1.9 m
(2) 3.85 m
(3) 2.79 m
(4) 2.90 m

Q31. Combustion of glucose $\left( \mathrm { C } _ { 6 } \mathrm { H } _ { 12 } \mathrm { O } _ { 6 } \right)$ produces $\mathrm { CO } _ { 2 }$ and water. The amount of oxygen (in g ) required for the complete combustion of 900 g of glucose is : [Molar mass of glucose in $\mathrm { gmol } ^ { - 1 } = 180$ ]
(1) 480
(2) 800
(3) 960
(4) 32

Q31. Identify the correct statements about p -block elements and their compounds. (A) Non metals have higher electronegativity than metals. (B) Non metals have lower ionisation enthalpy than metals. (C) Compounds formed between highly reactive nonmetals and highly reactive metals are generally ionic. (D) The non-metal oxides are generally basic in nature. (E) The metal oxides are generally acidic or neutral in nature. Choose the correct answer from the options given below :
(1) (B) and (D) only
(2) (A) and (C) only
(3) (D) and (E) only
(4) (B) and (E) only

Q31. Compare the energies of following sets of quantum numbers for multielectron system. (A) $\mathrm { n } = 4,1 = 1$ (B) $\mathrm { n } = 4 , \mathrm { l } = 2 ( \mathrm { C } ) \mathrm { n } = 3,1 = 1 ( \mathrm { D } ) \mathrm { n } = 3,1 = 2 ( \mathrm { E } ) \mathrm { n } = 4,1 = 0$ Choose the correct answer from the options given below :
(1)
(B) $>$ $( \mathrm { A } ) >$
(C) $>$ $( \mathrm { E } ) > ( \mathrm { D } )$
(2) (E) $< ($ C $) <$
(D) $< ($ A $) < ($ B )
(3) $( \mathrm { E } ) > ( \mathrm { C } ) > ( \mathrm { A } ) > ( \mathrm { D } ) > ( B )$
(4) (C) $<$ (E) $<$
(D) $<$ (A) $<$ (B)

Q31. The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency ' A ' $\times 10 ^ { 12 }$ hertz and that has a radiant intensity in that direction of $\frac { 1 } { { } ^ { \prime } \mathrm { B } ^ { \prime } }$ watt per steradian. ' A ' and ' B ' are respectively
(1) 540 and 683
(2) 450 and 683
(3) 450 and $\frac { 1 } { 683 }$
(4) 540 and $\frac { 1 } { 683 }$

Q32. The correct order of first ionization enthalpy values of the following elements is :
(A) O
(B) N (C) Be (D) F (E) B Choose the correct answer from the options given below :
(1) $\mathrm { E } < \mathrm { C } < \mathrm { A } < \mathrm { B } < \mathrm { D }$
(2) C $<$ E $<$ A $<$ B $<$ D
(3) B $<$ D $<$ C $<$ E $<$ A
(4) A $<$ B $<$ D $<$ C $<$ E

Q32. The correct order of the first ionization enthalpy is
(1) $\mathrm { Al } > \mathrm { Ga } > \mathrm { Tl }$
(2) $\mathrm { Ga } > \mathrm { Al } > \mathrm { B }$
(3) $\mathrm { Tl } > \mathrm { Ga } > \mathrm { Al }$
(4) $\mathrm { B } > \mathrm { Al } > \mathrm { Ga }$

Q32. The incorrect postulates of the Dalton's atomic theory are : (A) Atoms of different elements differ in mass. (B) Matter consists of divisible atoms. (C) Compounds are formed when atoms of different element combine in a fixed ratio. (D) All the atoms of given element have different properties including mass. (E) Chemical reactions involve reorganisation of atoms. Choose the correct answer from the options given below :
(1) (C), (D), (E) only
(2) (B), (D) only
(3) (A), (B), (D) only
(4) (B), (D), (E) only

Q32. Given below are two statements : Statement I : The metallic radius of Na is $1.86 \mathrm {~A} ^ { \circ }$ and the ionic radius of $\mathrm { Na } ^ { + }$is lesser than $1.86 \mathrm {~A} ^ { \circ }$. Statement II : Ions are always smaller in size than the corresponding elements. In the light of the above statements, choose the correct answer from the options given below :
(1) Both Statement I and Statement II are false
(2) Statement I is incorrect but Statement II is true
(3) Both Statement I and Statement II are true
(4) Statement I is correct but Statement II is false
Q33. List - I List - II
(A) ICl (I) T - shape
Match List I with List II
(B) $\mathrm { ICl } _ { 3 }$ (II) pyramidal Choose the correct answer from the
(C) $\mathrm { ClF } _ { 5 }$ (III) Pentagonal bipyramidal
(D) $\mathrm { IF } _ { 7 }$ (IV) Linear options given below :
(1) (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
(2) (A)-(I), (B)-(IV), (C)-(III), (D)-(II)
(3) (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
(4) (A)-(I), (B)-(III), (C)-(II), (D)-(IV)

Q32. The electron affinity value are negative for A . $\mathrm { Be } \rightarrow \mathrm { Be } ^ { - }$B. $\mathrm { N } \rightarrow \mathrm { N } ^ { - }$C. $\mathrm { O } \rightarrow \mathrm { O } ^ { 2 - }$ D. $\mathrm { Na } \rightarrow \mathrm { Na } ^ { - }$E. $\mathrm { Al } \rightarrow \mathrm { Al } ^ { - }$Choose the most appropriate answer from the options given below :
(1) D and E only
(2) A, B and C only
(3) A and D only
(4) A, B, D and E only

Q32. The ratio $\frac { K _ { P } } { K _ { C } }$ for the reaction : $\mathrm { CO } _ { ( \mathrm { g } ) } + \frac { 1 } { 2 } \mathrm { O } _ { 2 ( \mathrm {~g} ) } \rightleftharpoons \mathrm { CO } _ { 2 ( \mathrm {~g} ) }$ is :
(1) $\frac { 1 } { \sqrt { \mathrm { RT } } }$
(2) $( \mathrm { RT } ) ^ { 1 / 2 }$
(3) RT
(4) 1

Q32.

\multirow{6}{*}{Match List I with List II}		List - I		List - II	\multirow{6}{*}{Choose}
		(Elements)		(Properties in their respective groups)
	A.	Cl, S	I.	Elements with highest electronegativity
	B.	Ge, As	II.	Elements with largest atomic size
	C.	Fr, Ra	III.	Elements which show properties of both metals and non-metal
	D.	F, O	IV.	Elements with highest negative electron gain enthalpy

the correct answer from the options given below:
(1) A-II, B-I, C-IV, D-III
(2) A-III, B-II, C-I, D-IV
(3) A-IV, B-III, C-II, D-I
(4) A-II, B-III, C-IV, D-I

Q32. The shape of carbocation is :
(1) diagonal pyramidal
(2) trigonal planar
(3) tetrahedral
(4) diagonal

Q32. Given below are two statements : Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule. Statement (II) : $\mathrm { p } \pi - \mathrm { p } \pi$ bond formation is more prevalent in second period elements over other periods. In the light of the above statements, choose the most appropriate answer from the options given below :
(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is incorrect but Statement II is correct
(4) Statement I is correct but Statement II is incorrect