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.

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One gram mole of a gas at NTP occupies 22.4 L. This fact was derived from

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Important Questions on Some Basic Concepts of Chemistry

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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:

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In Carius method of estimation of halogens,

250 mg

of an organic compound gave

141 mg AgBr

. What is the percentage of bromine in the compound (atomic mass of

Ag = 108

and atomic number of

Br = 80

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The number of water molecules is maximum in

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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?

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Among the following pairs of compounds, the one that does not illustrate the law of multiple proportions, is

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A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed. The dried sample weighed 52 g. The formula of the hydrated salt is: (atomic mass, Ba = 137 amu, Cl = 35.5 amu)

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The amount of sugar

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

required to prepare

2 L

of its

0 .1 M

aqueous solution is:

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

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By heating

200 g

of metal carbonate,

112 g

of metal oxide on a gaseous compound are produced. Vapour density of the gaseous compound is

22

. How many moles of gaseous compound is produced in the reaction?

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The statement related to law of definite proportions is

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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

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56.0 L

of nitrogen gas is mixed with excess of hydrogen gas and it is found that

20 L

of ammonia gas is produced, The volume of unused nitrogen gas is found to be_____

L

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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}

)

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A compound with molecular mass

180

is acylated with

{CH}_{3} COCl

to get a compound with molecular mass

390

. The number of amino groups presents per molecule of the former compound is

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The amount of oxygen in

3.6

moles of water is:

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An organic compound contains

C, H

and

S

. The minimum molecular weight of the compound containing

8 %

Sulphur is

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The ratio of mass percent of

C and H

of an organic compound

(C_{X} H_{Y} O_{Z})

6 : 1 .

If one molecule of the above compound

(C_{X} H_{Y} O_{Z})

contains half as much oxygen as required to burn one molecule of compound

C_{X} H_{Y}

completely to

{CO}_{2}

and

H_{2} O .

The empirical formula of the compound

C_{X} H_{Y} O_{Z}

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

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Which of the following have same number of significant figures?
(A)

0.00253

(B)

1.0003

(C)

15.0

(D)

163

Choose the correct answer from the options given below

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Laws of Chemical Combination

Which of the following is an example of Law of multiple proportion?

One gram mole of a gas at NTP occupies 22.4 L. This fact was derived from

Important Questions on Some Basic Concepts of Chemistry

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