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

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.

EASY

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Find the total number and the total mass of protons in 34 mg of NH₃ at STP. (Mass of 1 p = 1.6726 x 10^-27 kg.) select any one of the following choices. Will the answer change if the temperature and pressure are changed?

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Important Questions on Structure of Atom

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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>Dalton's Idea of Atom

An amount of

18 g

glucose corresponds to:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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>Dalton's Idea of Atom

Consider the following reactions:

NaCl + K_{2} {Cr}_{2} O_{7} + \underset{(Conc.)}{H_{2} {SO}_{4}} \to (A) +

side products

(A) + N a O H \to (B) +

side products

(B) + \underset{(dilute)}{H_{2} S O_{4}} + H_{2} O_{2} \to (C) +

side products
The sum of the total number of atoms in one molecule each of

(A), (B)

and

(C)

is ________

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

The amount of oxygen in

3.6

moles of water is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

Which one of the followings has maximum number of atoms?

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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}

)

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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?

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

The number of water molecules is maximum in

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

Which one of the following will have the largest number of atoms?

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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>Dalton's Idea of Atom

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}

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

Which of the following has the largest number of moles?

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

One mole of carbon atom weighs

12 g

, the number of atoms in it is equal to, (Mass of carbon

- 12

1.9926 \times 10^{- 23} g)

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

The volume of oxygen at STP required to burn 2.4 g of carbon completely is:

EASY

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

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:

MEDIUM

Chemistry>Physical Chemistry>Structure of Atom>Dalton's Idea of Atom

The amount of sugar

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

required to prepare

2 L

of its

0 .1 M

aqueous solution is:

Find the total number and the total mass of protons in 34 mg of NH3 at STP. (Mass of 1 p = 1.6726 x 10-27 kg.) select any one of the following choices. Will the answer change if the temperature and pressure are changed?

Important Questions on Structure of Atom

Learn and Prepare for any exam you want !

Find the total number and the total mass of protons in 34 mg of NH₃ at STP. (Mass of 1 p = 1.6726 x 10^-27 kg.) select any one of the following choices. Will the answer change if the temperature and pressure are changed?