CBSE > Class 12 > Chemistry | CBSE Board | Homework Help

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

Ask Question

Why is cho group meta directing

Posted by Ram Chaudhary 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

K2ptcl6 is more stable than ni why

Posted by Priyank Dhakad 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

How cam define oxoacids of halogen

Posted by Aryan Verma 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

What are anomalous properties of fluorine

Posted by Srushti Torgal 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Snigdha Das 7 years, 3 months ago

Anomalous behaviour of fluorine : Fluorine differs from rest of the elements of its family due to (i) its small size (ii) highest electronegativity, (iii) low bond dissociation energy and (iv) absence of d-orbitals in the valence shell. The main points of difference are :

j. Fluorine is most reactive of all the halogens due to lower value of F−F bond dissociation energy ( F2=158, Cl2=243 , bromine = 192 and Iodine = 151 kJ mol–1 ) .

iii. Being the most electronegative element, it shows only an oxidation state of -1 and does not show positive oxidation states due to absence of d-orbitals in its valence shell. Other halogens show positive oxidation states of +1, +3, +5 and +7.

3Thank You

ANSWER

Why are cations smaller than their parents atom

Posted by Abhishek He 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Snigdha Das 7 years, 3 months ago

Cations are always smaller than their parent atoms this is because they have lesser electrons, while their nuclear charge remains the same. The remaining electrons are, therefore held more tightly by the protons in the nucleus and thus their radii.are smaller than the parent atoms. This is opposite in case of anions. Anions are always larger than their parent atoms because the addition of 1 or more electrons would result in increased repulsion among the electrons and a decrease in the effective nuclear charge.

2Thank You

ANSWER

Coordination entity

Posted by Bobby Gill 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Convert phenol to benzene

Posted by Anuradha Rai 7 years, 3 months ago

CBSE > Class 12 > Chemistry

2 answers

We Ayush 7 years, 3 months ago

Add zn dust

1Thank You

Megha Thood 7 years, 3 months ago

May be add kmno4

2Thank You

ANSWER

Why CuC2 is more stable than Cu2Cl2 .

Posted by Sansar Sumra 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Why tellurium dioxide and pllonium dioxide are insoluble in water?

Posted by Kashmiri Devi 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Why secondry valency are directional nature while primary valency are non directional nature.

Posted by Arti Vishwakarma 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Why sky is blue?

Posted by Vishu Sharma 7 years, 3 months ago

CBSE > Class 12 > Chemistry

2 answers

Deepak Jindal 7 years, 3 months ago

How you written this answer .... From yourself or from the net

1Thank You

Yogita Ingle 7 years, 3 months ago

The blue colour of sky is due to the scattering of light by small particles of the atmosphere (air molecules) when the light is incident on particles whose size is smaller than the wavelength of light, it is scattered.

According to Rayleigh law, the intensity of scattered light is inversely proportional to the fourth power of wavelength.

As the wavelength of blue colour is smallest and that of red light is longest, the blue light is scattered most and the red light is scattered least.

The scattered blue light reaching the eye gives the appearance of a blue sky. The sky will appear black in the absence of earth’s atmosphere because no scattering of any colour takes place in that case. While flying in an aeroplane one can observe the sky to be black at high altitudes.

0Thank You

ANSWER

Why NH3 act as a ligand?

Posted by Sourabh Verma 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Arti Vishwakarma 7 years, 3 months ago

Because NH3 is a lone pair electron

1Thank You

ANSWER

How to study for class 12 which lessons are main for this subject

Posted by Ram Chandra Behera 5 years, 8 months ago

CBSE > Class 12 > Chemistry

1 answers

Satyam Op Prajapati 7 years, 3 months ago

Carbonyl compound , aldehyde and ketones , solution, Alcohol and phenols, chemical kinetics

0Thank You

ANSWER

What is the difference between Pyrometallurgy and electrometallurgy

Posted by Sakshi Sinha 4 years, 6 months ago

CBSE > Class 12 > Chemistry

1 answers

Sia ? 4 years, 6 months ago

Pyrometallurgy involves high temperature processes where chemical reactions take place. Electrometallurgy involves metallurgical processes that take place in some form of electrolytic cell.

0Thank You

ANSWER

Acidity of carboxylic acid

Posted by Mukesh Singh 5 years, 8 months ago

CBSE > Class 12 > Chemistry

2 answers

Karan Suyal 5 years, 8 months ago

Eno kha le beta

4Thank You

Anjana Sherawat 7 years, 3 months ago

Is highest among organic compounds

4Thank You

ANSWER

Why crystalline solid have definite heat of fusion???

Posted by G K 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Yogita Ingle 7 years, 3 months ago

Crystalline solids have same properties in all direction of the crystal, they have a regular and repetitive arrangement of constituent particles, and thus a sharp melting point. They do not flow before melting. Hence, they have definite heat of fusion.
Whereas, amorphous solids do not have a regular pattern of constituent particles and thus do not have a sharp melting point. They melt over a range of temperature and start to flow without completely changing into liquid. Hence, they do not have definite heat of fusion.

2Thank You

ANSWER

An Element crystallizes in fcc with cell edge of 250pm. Calculate density if 300gm of this element contains 2*10^24 atoms.

Posted by Mani Manohar 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Mani Manohar 7 years, 2 months ago

0Thank You

ANSWER

What happrns when vapour of ethanol is passed through hot copper???

Posted by Shubham Raina 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

We Ayush 7 years, 3 months ago

Give ethanal

0Thank You

ANSWER

Volumetric experiments

Posted by Laajo Gupta 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

A crystalline structure has radius (r+/r) in the range of 0.225-0.414.the coordination number and arrangement of anions and cations are

Posted by Durgesh Yadav 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Pratibha Ydv 7 years, 3 months ago

Coordination no. = 4 Arrangement= tetrahedral and example is ZnS(sphalerite).

2Thank You

ANSWER

What is population?Give example

Posted by Pranjal Shukla 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

How do u account for the increase in molar conductivity of electrolyte on dilution?

Posted by Aastha Sinha 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Leaching with reduction of aluminium is known as__________________ method.

Posted by Pooja Sarkar 7 years, 3 months ago

CBSE > Class 12 > Chemistry

2 answers

Pooja Sarkar 7 years, 3 months ago

Dont u think its pyrometallurgy

0Thank You

Hy Shona 7 years, 3 months ago

Chromatographic method

0Thank You

ANSWER

conversion of ether into alcohol

Posted by Suffyan Ansari 7 years, 3 months ago

CBSE > Class 12 > Chemistry

2 answers

Pooja Sarkar 7 years, 3 months ago

R--O--R +HI----> R---OH + R-I

2Thank You

We Ayush 7 years, 3 months ago

Ether to alcohol can be converted by reactiong with hi which give alcohol and alkyl iodide.in first step protonation takes place and then I- will act as nucleophile and take through either sn1 and sn2 mechanism.you have to see which mechanism it will follow

0Thank You

ANSWER

What happen when a freshly prepared precipitates of Fe(OH)3 is shaken with small amount of FeCl3 solution?

Posted by Aayush Kaushal 7 years, 3 months ago

CBSE > Class 12 > Chemistry

2 answers

Pooja Sarkar 7 years, 3 months ago

Peptization takes place.

3Thank You

Nitesh Tiwari 7 years, 3 months ago

H2o loss

2Thank You

ANSWER

Type some question of solution .plz i need them for my preparation.

Posted by Hy Shona 7 years, 3 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Why PH3 as lower B.P than NH3 ?

Posted by Pradhumn Kumar Chaudhary 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Yogita Ingle 7 years, 3 months ago

Boiling point of PH₃ is lower than NH₃ due to the fact that NH3 has Hydrogen Bonding which increses the bond strength and thus increases the Boiling Point , while in case of PH₃ , no hydrogen bonding is possible.

4Thank You

ANSWER

How to distinguish between major and minor product in organic

Posted by Jagdeep Singh 7 years, 3 months ago

CBSE > Class 12 > Chemistry

3 answers

We Ayush 7 years, 3 months ago

Steric factor

0Thank You

Nitesh Tiwari 7 years, 3 months ago

Boiling point

0Thank You

Nikhil Sachdeva 7 years, 3 months ago

More stable product is ie sadjeff pdt is generally major product

4Thank You

ANSWER

What is reimen teiman reaction?

Posted by Harsh Mathur 7 years, 3 months ago

CBSE > Class 12 > Chemistry

1 answers

Ayush Parija 7 years, 3 months ago

Riemer tiemann reaction in which phenol is treated with choloroform in presence of aq koh to salicylaldehyde .in this reaction base koh react with chloroform to produce dichloro carbene via e1 cb elimination.then koh acts as base to produce phenoxide ion .then resonance structure is drawn and negative charge occurs at ortho position then it attacks di chloro carbene .it produce gem hallide on treatment with koh gem hallide then conveets to cho group and salicylaldehyde is formed

1Thank You

ANSWER

blue print of chemistary 1st part 12th cbse

Posted by Rahul Singh Rathore 7 years, 3 months ago

CBSE > Class 12 > Chemistry