CBSE > Class 11 > Chemistry | CBSE Board | Homework Help

Ask questions which are clear, concise and easy to understand.

Ask Question

An organic compound has a composition of compound as carbon is equals to40.6 8% and hydrogen is equals to 5.085 and oxygen is equals to 50 4.22 percent the vapour density of a compound is 59 calculate the molecular formula of a compound

Posted by Tript Preet???? 6 years, 6 months ago

CBSE > Class 11 > Chemistry

1 answers

Sia ? 6 years, 6 months ago

Given Percentage of C= 40.687% , Percentage of H = 5.085%.

Therefore, Percentage of O = 100 - (40.687+5.085) = 54.228%.
Step I: To calculate the empirical formula of the compound.

<th scope="col">Element</th> <th scope="col">Symbol</th> <th scope="col">Percentage of element</th> <th scope="col">Moles of the element

Carbon	C	40.687	{tex}\frac { 40.687 } { 12 } = 3.390{/tex}	{tex}\frac { 3.390 } { 3.389 } = 1{/tex}	2
Hydrogen	H	5.085	{tex}\frac { 5.0885 } { 1 } = 5.085{/tex}	{tex}\frac { 5.085 } { 3.389 } = 1.5{/tex}	3
Oxygen	O	16	{tex}\frac { 54.228 } { 16 } = 3.389{/tex}	{tex}\frac { 3.389 } { 3.389 } = 1{/tex}	2

Since, ration of C : H : O = 2 :3 :2.

{tex}\therefore{/tex} An empirical formula is C₂H₃O₂.
Step II: The empirical formula of the compound = C₂H₃O₂.
{tex}\therefore{/tex} Empirical formula mass = 2 {tex}\times{/tex} C +3 {tex}\times{/tex} H + 2{tex}\times{/tex} O = {tex}( 2 \times 12 ) + ( 3 \times 1 ) + ( 2 \times 16 ) = 59{/tex}
Step III: To calculate the molecular mass of the salt
The vapour density of the compound = 59 (Given)
Using the relation between vapour density and molecular mass.

Therefore, Molecular mass of compound = 2 {tex}\times{/tex} vapour density of compound = 2 {tex}\times{/tex} 59 = 118
Step IV: The value of n = {tex}\frac { \text { molecular mass } } { \text { empirical formula mass } } = \frac { 118 } { 59 } = 2{/tex}
Step V: Calculation of the molecular formula of the salt,
Molecular formula = n {tex}\times{/tex} empirical formula = {tex}2 \times \mathrm { C } _ { 2 } \mathrm { H } _ { 3 } \mathrm { O } _ { 2 } = \mathrm { C } _ { 4 } \mathrm { H } _ { 6 } \mathrm { O } _ { 4 }{/tex}
Thus, the molecular formula is C₄H₆O₄.

3Thank You

ANSWER

What is pure substance

Posted by Digvijaysingh Kushwah 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

Mg+2 is smaller than O-²,although both have same electronic configuration. Why?

Posted by Prabhjot Singh 6 years, 6 months ago

CBSE > Class 11 > Chemistry

2 answers

Kanha Gupta 6 years, 6 months ago

Mg+2 is smaller because it has 12 protons and 10 electrons and oxygen ion has 8 electrons and 10 electrons...

1Thank You

Digvijaysingh Kushwah 6 years, 6 months ago

0Thank You

ANSWER

Which is good reference for chemistry and physics?

Posted by Vivek Kashyap 6 years, 6 months ago

CBSE > Class 11 > Chemistry

3 answers

Pinku Meena 6 years, 6 months ago

You can buy DC pandey for physics if you are preparing for NEET AIIMS or JEE

1Thank You

Kanha Gupta 6 years, 6 months ago

If you are preparing for NEET, AIIMS or JEE you can buy allens modules with ncert then solve as much questions as you can..

2Thank You

Shriya Yadav 6 years, 6 months ago

Ncert is the only book which gives full marks with short answers.

1Thank You

ANSWER

Avogadro law full explanation

Posted by Nitin Jarewal 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

Transition elements kya hota h?

Posted by Sakshi Singh 6 years, 6 months ago

CBSE > Class 11 > Chemistry

3 answers

Sia ? 6 years, 6 months ago

Properties of transition elements include:
have large charge/radius ratio;
are hard and have high densities;
have high melting and boiling points;
form compounds which are often paramagnetic;
show variable oxidation states;
form coloured ions and compounds;
form compounds with profound catalytic activity;

0Thank You

Sakshi Singh 6 years, 6 months ago

I want 2 know about transition elements

0Thank You

Sia ? 6 years, 6 months ago

Elements in which the last electron enters the d-orbitals, are called d-block elements. These elements have general outer electronic configuration (n-1)d^1-10 ns^0-2. Zn, Cd and Hg which have general electronic configuration, (n-1) d¹⁰ns² do not show most of the properties of transition elements. d-orbitals in these elements are completely filled in the ground state as well as in their common oxidation states. Thus, on the basis of properties, all transition elements are d-block elements but on the basis of electronic configuration, all d- block elements are not transition elements.

1Thank You

ANSWER

As we go Left to right in periodic table, atomic size decreases so why oxygen has larger atomic size than nitrogen

Posted by Aarushi Sharma 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

Explain H2O is liquid at ordinary temperature While H2S is gas?

Posted by Manish Gupta 6 years, 6 months ago

CBSE > Class 11 > Chemistry

1 answers

Sia ? 6 years, 6 months ago

Due to greater electronegativity of O than S, H₂O undergoes extensive intermolecular H-bonding. As a result, H₂O is a liquid at room temperature. In contrast, H₂S does not undergo H-bonding. It exists as discrete molecules which are held together by weak Van der Waals forces of attraction. To break these forces of attraction, only a small amount of energy is required. Therefore, H₂S is a gas at room temperature.

2Thank You

ANSWER

Explain ionic compounds are generally soluble in polar solvent?

Posted by Manish Gupta 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

Why d-block elements are called transition element ?

Posted by Deepjyoti Borthakur 6 years, 6 months ago

CBSE > Class 11 > Chemistry

1 answers

Sia ? 6 years, 6 months ago

1Thank You

ANSWER

Differentiate between molarity and molality??

Posted by Vaidehi Bilgaiyan 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

What is effective nuclear charge?

Posted by Peer Muheeb 6 years, 6 months ago

CBSE > Class 11 > Chemistry

3 answers

Js Multani 6 years, 6 months ago

The charge the reach to the outermost electrons even after the screening effect has taken place . The charge is known as the effective nuclear charge.

0Thank You

Dheeraj 12A4696 6 years, 6 months ago

The charge which is feel by the e- in the last cell of an atom is called effective nuclear charge

1Thank You

Pinku Meena 6 years, 6 months ago

Difference of nuclear charge and screening effect

0Thank You

ANSWER

In a mixture of gases , the volume content of a gas is 0.06% at STP. Calculate the number of molecules of the gas in 1L of the mixture

Posted by Happy Dhillon 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

If NA is avogadro `s number then number of valency electron in 4.2 g of nitride ions (N3-)

Posted by Happy Dhillon 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

The mass of a photon with a wavelength equal to 1.54 ×10 power -8

Posted by Happy Dhillon 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

If 170kg of NH3 is heated is excess of oxygen then the volome of H2O produced in 1st reaction STP is

Posted by Happy Dhillon 6 years, 6 months ago

CBSE > Class 11 > Chemistry

0 answers

ANSWER

Can you give step wise explanation of the discovery of electrons plz

Posted by Japisher Singh 6 years, 6 months ago

CBSE > Class 11 > Chemistry

2 answers

Shubham Kumar 6 years, 6 months ago

Electron was descovered by jj thomson by expriement with discharge tube. When thomson put positively charge substance on one side of discharge tube he saw that particle from cathod ray bend towards that positively charge substance. From this he came to know that particle from cathod ray contain negatively charge particles and called them as electron

2Thank You

Japisher Singh 6 years, 6 months ago

Plz answer at the soonest

2Thank You

ANSWER

The temperature of 1 litre water is 80 degree Celsius and the temperature of 3litre water is 40degree celsius ,when they are mixed with each other what is the equivalent temperature of the whole water

Posted by Jyoti Jaiswal 6 years, 6 months ago

CBSE > Class 11 > Chemistry