Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 10

MEDIUM

11th CBSE

IMPORTANT

Earn 100

The value of Planck's constant is $6.63 x 10^{- 34} Js$ . The speed of light is $3 x 10^{17} nm s^{- 1}$ . Which value is closest to the wavelength in nanometer of a quantum of light with frequency of $6 x 10^{15} s^{- 1} ?$

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Important Questions on Structure of Atom

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 11

Calculate the wavelength of the light required to break the bond between two chlorine atoms in a chlorine molecule. The

Cl - Cl

bond energy is

243

kJ {mol}^{- 1}

(h = 6.6 \times 10^{- 34} Js, c = 3 \times 10^{8} {ms}^{- 1}

,

Avogadro' s number = 6.02 \times 10^{23} {mol}^{- 1})

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 12

A

600 W

mercury lamp emits monochromatic radiation of wavelength

313.3 nm

. How many photons are emitted from the lamp per second ?

(h = 6.626 x 10^{- 34} Js, velocity of light = 3 x 10^{8} {ms}^{- 1})

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 13

When the frequency of the incident radiation on a metallic plate is doubled, KE of the photoelectrons will be

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 14

Photoelectric emission is observed from a metal surface with incident frequencies

v_{1}

and

v_{2}

where

v_{1} > v_{2}

. If the kinetic energies of the photoelectrons emitted in the two cases are in the ratio

2 : 1

, then the threshold frequency

v_{0}

of the metal is

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 15

The wavelength of the electron emitted, when in a hydrogen atom, electron falls from infinity to stationary state 1, would be (Rydberg constant

= 1 \cdot 097 \times 10^{7} m^{- 1})

MEDIUM

11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 16

The frequency of light emitted for the transition

n = 4

to

n = 2

of

{He}^{+}

is equal to the transition in

H

atom corresponding to which of the following

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 17

Based on the equation

E = - 2.178 \times 10^{- 18} J (\frac{z^{2}}{n^{2}})

certain conclusions are written. Which of them is not correct?

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11th CBSE

IMPORTANT

Pradeep's Chemistry Vol 1>Chapter 2 - Structure of Atom>Competition Focus>Q 18

The shortest wavelength in hydrogen spectrum of Lyman series when

R_{h} = 109678 {cm}^{- 1}

is