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$120$ grams of an organic compound contains $40 % C$ by mass, $8 g$ -atom of $H$ and $64$ grams of oxygen, The molecular formula of compound is :

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Important Questions on Some Basic Concepts of Chemistry

HARD

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

The formulae of an oxide of an element

M

MO

. The formulae of its phosphate is

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

If the vapour density of the carbon containing gaseous substance is

13

, which of the following is its molecular formula?

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

An element X with atomic number

13

combines with another element Y of atomic number

17

. The formula of the compound formed and the nature of the bond will be:

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

An organic compound contains

80 %

(by wt.) carbon and remaining percentage of hydrogen. The right option for the empirical formula of this compound is: [Atomic wt. of

C

12

and of

H

1

]

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

An organic compound contains

60 % C; 4.48 % H

and

35.5 % O .

Its empirical formula is

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

A pure compound contains

2.4 g

C, 1.2 \times 10^{23}

atoms of

H, 0.2

moles of oxygen atoms. Its empirical formula is

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

The molecular formula of chloride of a metal M is

{MCl}_{2}

. The molecular formula of an oxide of M will be:

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

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

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

Molecular formula of a compound is

C_{6} H_{18} O_{3}

. Find its empirical formula.

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

Find the empirical formula and the molecular formula of an organic compound from the data given below:

$C = 75.92 %, H = 6.32 % and N = 17.76 %$

The vapour density of the compound is $39.5$ . $[C = 12, H = 1, N = 14]$

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

Compound $A$ contains $8.7 %$ Hydrogen, $74 %$ Carbon and $17.3 %$ Nitrogen. The molecular formula of the compound is, Given : Atomic masses of $C, H$ and $N$ are $12, 1$ and $14$ amu respectively.

The molar mass of the compound $A$ is $162 g {mol}^{- 1}$ .

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

The empirical formula and molecular mass of a compound are

{CH}_{2} O

and

180 g

respectively. The molecular formula of the compound will be

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

Number of hydrogen atoms per molecule of a hydrocarbon A having

85.8 %

carbon is (Given : Molar mass of

A = 84 g {mol}^{- 1}

)

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

A compound has the following composition by weight;

N a = 18.60 %, S = 25.80 %, H = 4.02 %

and

O = 51.58 %

Assuming that all the hydrogen atoms in the compound are part of water of crystallization, the correct molecular formula of the compound is

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

When a hydrocarbon

A

undergoes combustion in the presence of air, it requires

9.5

equivalents of oxygen and produces

3

equivalents of water. What is the molecular formula of

A

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

An organic compound contains

24 %

carbon,

4 %

hydrogen and remaining chlorine. Its empirical formula is

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Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

1.25 g of a metal (M) reacts with oxygen completely to produce 1.68 g of metal oxide. The empirical formula of the metal oxide is [Molar mass of M and O are

69.7 g m o l^{- 1}

and

16.0 g m o l^{- 1}

, respectively]

EASY

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

A solution of a substance 'X' is used for whitewashing.

(a) Name the substance 'X' and write its formula.

(b) Write the reaction of the substance with water.

MEDIUM

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

In a compound

C, H

and

N

are present in

9 : 1 : 3.5

by weight. If molecular weight of compound is

108

, the molecular formula of compound is

HARD

Chemistry>Physical Chemistry>Some Basic Concepts of Chemistry>Empirical and Molecular Formulae

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}

120 grams of an organic compound contains 40% C by mass, 8 g-atom of H and 64 grams of oxygen, The molecular formula of compound is :

Important Questions on Some Basic Concepts of Chemistry

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$120$ grams of an organic compound contains $40 % C$ by mass, $8 g$ -atom of $H$ and $64$ grams of oxygen, The molecular formula of compound is :