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A radioactive nucleus has a decay constant lambda=0.345 day. How long would it take the nucleus to decay 75% of its initial amount?

Posted by Amisha Patidar 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Sourin Roy 8 years, 1 month ago

3 days. formula for halflife = 0.693/(lambda) which is equal to 2 days. So the nucleus decays 50% in 2 days and 75% in 3 days.

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The magnitude of heat of solution remains constant on addition of solvevt to it .Why?

Posted by Pranav Rastogi 8 years, 1 month ago

CBSE > Class 12 > Chemistry

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Why there is striking similarity in successive members of transition series.

Posted by Rochie Joshi 8 years, 1 month ago

CBSE > Class 12 > Chemistry

0 answers

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State raoult's law. How is it formulated for solutions of non-volatile solute?

Posted by Shreya Sakshi 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Utkarsh Mathur 8 years, 1 month ago

Raoults law for a solution of volatile liquids states that partial vapour pressure of each component in solution is directly proportional to mole fraction

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Ozone is thermodynamically unstable with respect to oxygen. Explain

Posted by Mayank Tiwari 8 years, 1 month ago

CBSE > Class 12 > Chemistry

2 answers

Deepak Chander Joshi 8 years, 1 month ago

Decomposition of ozone into oxygen result in highly -be Gibbs energy

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Jin Kazama 8 years, 1 month ago

O3 -------> O2 + [O] ?

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Is meisomeric effect and resonance effect are same or different?

Posted by Kanak Tiwari 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Kanak Tiwari 8 years, 1 month ago

Please answer me

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How para chloro benzoic acid is more acidic than para fluoro benzoic acid

Posted by Kanak Tiwari 8 years, 1 month ago

CBSE > Class 12 > Chemistry

0 answers

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What is an azeotropic mixture

Posted by Arman Singh Thakkr 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Sirshak Samantaray 8 years, 1 month ago

A binary soln of liquids which boils at a temp without undergoing any change in its composition

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Why amino acids has high melting point

Posted by Aniket Rajoria 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Aniket Rajoria 8 years, 1 month ago

Because amino acids are found normally in the form of zwitterions which is neither a amine nor carboxylic acid and is itself a salt . As salt is highly polar molecules and hence have high melting point

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I want solution of previous years paper yet I got only few of them.

Posted by Mannat Goyal 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Rochie Joshi 8 years, 1 month ago

App m ni mile kya .last yr paprs m honge .

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Enthalpy of atomization.

Posted by Vinay Pratap 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Insha Fatima 8 years, 1 month ago

The energy required to break down the molecules into atom or the heat released as a result of atomisation is called enthalpy of atomisation

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what is piezo electric crystals ?

Posted by Sangeeta Rathore 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Jin Kazama 8 years, 1 month ago

Small babies boat give some strange sound like chi chi , it is piezo electricity and this crystals are P.E.crystals ?

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Why transition metal show variable Oxidation State

Posted by Vedant Shukla 8 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Simran Singh 8 years, 1 month ago

Due to presence of unpaired electron in d orbital.

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What is +i and -i effect please explain in brief giving example

Posted by Priysnshu Diwakar 8 years, 1 month ago

CBSE > Class 12 > Chemistry

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What is +i effect or -i effect please explain in brief giving example

Posted by Priysnshu Diwakar 8 years, 1 month ago

CBSE > Class 12 > Chemistry

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Difference between RCN&RNC..

Posted by Ashwani Kumar Maurya 8 years, 1 month ago

CBSE > Class 12 > Chemistry

3 answers

Deepak Chander Joshi 8 years, 1 month ago

RCN is a alkylcyanide and RNC is alkylisocyanide

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Ashwani Kumar Maurya 8 years, 1 month ago

Name kya hoga? Kaise reaction me participate krenge?

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Kanak Tiwari 8 years, 1 month ago

in RCN alkyl group is directly attached with carbon atom and have a triple Bond nitrogen atom Where as in RNC alkyl group is directly attached with nitrogen atom and have triple bond with carbon atom

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Why para chloro benzoic acid is less acidic than para chloro benzoic acid

Posted by Kanak Tiwari 8 years, 1 month ago

CBSE > Class 12 > Chemistry