If Avogadro number N A , is changed from 6.022 × 10 23 m o l - 1 to 6.022 × 10 20 m o l - 1 , this would change:

The definition of mass in units of grams

The ratio of chemical species to each other in a balanced equation.

The ratio of elements to each other in a compound.

5 moles of A B 2 weigh 125 × 10 - 3 k g and 10 moles of A 2 B 2 weigh 300 × 10 - 3 k g . The molar mass of A ( M A ) and molar mass of B ( M B ) in k g m o l - 1 are:

M A = 5 × 10 - 3 and M B = 10 × 10 - 3

M A = 25 × 10 - 3 and M B = 50 × 10 - 3

M A = 50 × 10 - 3 and M B = 25 × 10 - 3

M A = 10 × 10 - 3 and M B = 5 × 10 - 3

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Loss of electron from hydrogen atom results in nucleus of ~ 1 . 5 × 10 – 3 pm size. Reason R: Proton H + always exists in combined form. In the light of the above statements, choose the most appropriate answer from the options given below:

Both A and R are correct but R is NOT the correct explanation of A

Both A and R are correct and R is the correct explanation of A

A is correct but R is not correct

A is not correct but R is correct

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The mass of 1 mole of electrons is

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Important Questions on Structure of Atom

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

A mixture of gases contains

H_{2}

and

O_{2}

gases in the ratio of

1 : 4

(w/w). What is the molar ratio of the two gases in the mixture?

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The amount of sugar

(C_{12} H_{22} O_{11})

required to prepare

2 L

of its

0 .1 M

aqueous solution is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

If Avogadro number

N_{A}

, is changed from

6.022 \times 10^{23} m o l^{- 1}

6.022 \times 10^{20} m o l^{- 1}

, this would change:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The amount of oxygen in

3.6

moles of water is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

Amongst the following statements, that which was not proposed by Dalton was :

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

An unknown chlorohydrocarbon has 3.55 % of chlorine. If each molecule of the hydrocarbon has one chlorine atom only; chlorine atoms present in 1 g of chlorohydrocarbon are :(Atomic wt. of

Cl = 35 .5 u;

Avogadro constant

= 6 .023 \times 10^{23} {mol}^{- 1}

)

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The number of water molecules is maximum in

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The flocculation value of

H C l

for arsenic sulphide

s o l

30 m m o l L^{- 1}

. If

H_{2} S O_{4}

is used for the flocculation of arsenic sulphide, the amount, in grams, of

H_{2} S O_{4}

250 m l

required for the above purpose is ________. (Round off to two digits after decimal.)
(molecular mass of

H_{2} {S O}_{4} = 98 g / m o l

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

Among the following, the correct statement about cathode ray discharge tube is

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The number of times the comparative mass of a neutron is heavier than an electron is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is 1 : 4. The ratio of number of their molecules is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

In Millikan's oil drop experiment, the forces acting on the oil drop are?

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required to achieve

10 p p m

of iron in

100 k g

of wheat is ____________. (Up to two decimal place)
Atomic weight:

F e = 55.85; S = 32.00; O = 16.00

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

Suppose the elements

X

and

Y

combine to form two compounds

X Y_{2}

and

X_{3} Y_{2}

. When

0.1 mole

X Y_{2}

weighs

10 g

and

0.05 mole

X_{3} Y_{2}

weighs

9 g

, the atomic weights of

X

and

Y

are

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

5

moles of

A B_{2}

weigh

125 \times 10^{- 3} k g

and

10

moles of

A_{2} B_{2}

weigh

300 \times 10^{- 3} k g

. The molar mass of A

(M_{A})

and molar mass of

B (M_{B})

k g {m o l}^{- 1}

are:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

0.023 \times 10^{22}

molecules are present in

10 g

of a substance

{}^{'}x^{'} .

The molarity of a solution containing

5 g

of substance 'x' in 2 L solution is

_________\times 10^{- 3}

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The first and second ionisation enthalpies of a metal are

496

and

4560 k J m o l^{- 1}

, respectively. How many moles of

H C l

and

H_{2} S O_{4},

respectively, will be needed to react completely with

1

mole of the metal hydroxide?

HARD

Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Loss of electron from hydrogen atom results in nucleus of $~ 1.5 \times 10^{- 3} pm$ size.

Reason R: Proton $(H^{+})$ always exists in combined form.

In the light of the above statements, choose the most appropriate answer from the options given below:

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

Electrons in a cathode ray tube have been emitted with a velocity of $1000 {ms}^{- 1}$ . The number of following statements which is/are true about the emitted radiation is

Given : $h = 6 \times 10^{- 34} Js, m_{e} = 9 \times 10^{- 31} kg$

(A ) The deBroglie wavelength of the electron emitted is $666.67 nm$

(B ) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube.

(D ) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube..

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Chemistry>Physical Chemistry>Structure of Atom>Subatomic Particles

The number of neutrons in

{}_{13}^{27}{Al}

The mass of 1 mole of electrons is

Important Questions on Structure of Atom

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