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

Ammonia is prepared using the Haber’s process. The conditions required to maximize the yield of ammonia are as follows: 1 In accordance to Le Chatelier’s principle ,low temperature will shift the equilibrium to the right because the reaction is exothermic.This gives greater yield of ammonia.Therefore a temperature of about 450°C will be optimal for the preparation of ammonia. 2 High pressure on the reaction at equilibrium favours the shift of the equilibrium to the right because the forward reaction proceeds with a decrease in number of moles.Hence a pressure of about 200 atm will be optimal for the higher yield of ammonia. 3 A catalyst should be used to increase the rate of reaction & to quickly attain equilibrium.For eg as iron oxide mixed with small amounts of K2O and Al2O3 can be used as catalyst. 4 N2 & H2 gases should be pure in nature to increase the yield of ammonia.

4Thank You

ANSWER

What are azeotropes? Can someone explain with an example?!

Posted by Khushboo Barwar 7 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Sahana Sankaranarayanan 7 years, 1 month ago

Azeotropes are binary mixtures having the same composition in liquid and vapour phase and boil at a constant temperature. They are of 2 types Minimum boiling azeotropes: these are binary mixtures whose boiling point is less than either of the two components. The non ideal solutions which show a large positive deviation from raoults law form minimum boiling azeotropes at specific composition eg. a mixture of 94.5% ethyl alcohol and 4.5% water by volume. Maximum boiling azeotropes: these are binary mixtures whose boiling point is more than either of the two components. The solutions that show large negative deviation from raoults law form maximum boiling azeotropes at a specific composition eg. a mixture of 68% hno3 and 32% water by mass.

3Thank You

ANSWER

10g. NaCl and 10g sucrose is added to two beakers containing 100ml water each. In which case there is more elevation in b.p and why ?

Posted by Aditi Panchal 7 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Yash Aggarwal 7 years, 1 month ago

In Case of NaCl in water because being electrolytic NaCl will dissociates into ions and hence 2≥i≥1 while sucrose is non eletrolytic hence will not dissociate

3Thank You

ANSWER

Why does glass considered as super cooled liquid

Posted by Shubham Sk 7 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Sanskriti S 7 years, 1 month ago

glass, being amorphous solid, has tendency to flow(with very high viscosity)

6Thank You

ANSWER

Whqt are antagonists and agonists???

Posted by Shivam Keshri 7 years, 1 month ago

CBSE > Class 12 > Chemistry

3 answers

Mahi Cheeku. ?? Msd Vk 7 years, 1 month ago

1.Agonist and antagonist act in opposite directions. When agonist produces an action, antagonist opposes the action. 2. Agonist works when the muscles relax and antagonist works when muscles contract. 3. While agonists stimulate an action, antagonists sit idle, doing nothing. 4. An agonist ties to a receptor site and causes a response whereas an antagonist works against the drug and blocks the response. 5. Agonists are also chemicals or reactions, which help in binding and also altering the function of the activity of receptors. On the other hand, antagonists though help in binding receptors, they do not alter its activity. 6. When agonist is a compound that impersonate the action of neurotransmitter, antagonist blocks the action of neurotransmitter. 7. Agonist has been derived from late Latin word agnista, which means contender. Antagonist has been derived from Latin antagonista and from Greek antagonistes, which means “competitor, rival or opponent.”

4Thank You

Sanskriti S 7 years, 1 month ago

antagonists - drugs that bind to the receptor site & inhibit its natural function ; agonists - drugs that copy the natural messenger by switching on the receptor

5Thank You

Rohindh Kishore 7 years, 1 month ago

Drugs

2Thank You

ANSWER

Dry ether is used in wurtz reaction.why?

Posted by Purva Sharma 7 years, 1 month ago

CBSE > Class 12 > Chemistry

4 answers

Mahi Cheeku. ?? Msd Vk 7 years, 1 month ago

Wurtz reaction always want a sodium metal which is highly reactive...so it needs less reactive solvent for it to react .dry ether is less reactive ,non polar and aprotic...that is why it is used as solvent...

3Thank You

Gaurav Seth 7 years, 1 month ago

In wurtz reaction, pure sodium is used which is highly violent towards water therefore dry ether is used.

3Thank You

Suhani Rana? 7 years, 1 month ago

Na metal is used in wurtz reaction which is highly reactive so we need a solvent which do not react with Na.morever if we do not use dry ether then sodium metal react with water to form oxides and hydroxides and disturb the reaction.. and dry ether is used as a catalyst too.

3Thank You

Sanskriti S 7 years, 1 month ago

grignard reagents have high affinity of water. Even in small traces of moisture, it will get converted into hydrocarbon. So ethers are used to provide anhydrous conditions

3Thank You

ANSWER

Marking scheem

Posted by Anuja Inamdar 7 years, 1 month ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Name two poisonous gases which can be prepared from chlorine gas

Posted by Lavanya K 7 years, 1 month ago

CBSE > Class 12 > Chemistry

3 answers

Sahana Sankaranarayanan 7 years ago

Shld we learn the formula too?

0Thank You

Yash Tyagi 7 years, 1 month ago

Phosgene COCl2

1Thank You

Sanskriti S 7 years, 1 month ago

phosgene, tear gas, mustard gas

3Thank You

ANSWER

What is the role of ph in coupling reaction?

Posted by Purva Sharma 7 years, 1 month ago

CBSE > Class 12 > Chemistry

4 answers

Sanskriti S 7 years, 1 month ago

does not** occur at N of amine

3Thank You

Sanskriti S 7 years, 1 month ago

hope u 're getting it...

1Thank You

Sanskriti S 7 years, 1 month ago

coupling reaction with phenol is carried out in weakly basic medium (pH 9-10), whereas in weakly acidic medium(pH 4-5)with amines. Diazonium ions act as electrophiles & phenols and amines act as nucleophiles. Basic medium with phenols deprotonate phenol and make it nucleophile. Acidic medium with amines protonates amino group of amines so that attack does occur at N of amine(attack must be at N of diazo group).

7Thank You

Sanskriti S 7 years, 1 month ago

good que!!!

2Thank You

ANSWER

What is van arkel method???

Posted by Anjali Sharma 7 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Suhani Rana? 7 years, 1 month ago

Van arkle method is used to get pure Ti or Zr by this method oxygen and nitrogen present in Ti or Zr are removed

3Thank You

ANSWER

Is polyhallogen compounds topic from haloalkenes& haloarenes & some comercially important alchols topic from alcohols phenols & ethers there in cbse board syllabus.

Posted by Ayushi Kachhwaha 7 years, 1 month ago

CBSE > Class 12 > Chemistry

2 answers

Sanskriti S 7 years, 1 month ago

yes they are included

3Thank You

Shivam Bhati 7 years, 1 month ago

No, l dont think it so

1Thank You

ANSWER

Can I use "1F= 96500C" in exam??

Posted by Sayeda Iram Ateeq 7 years, 1 month ago

CBSE > Class 12 > Chemistry

3 answers

Sahana Sankaranarayanan 7 years, 1 month ago

Yes

0Thank You

Dharshika As 7 years, 1 month ago

yes

0Thank You

Sanskriti S 7 years, 1 month ago

yes?

4Thank You

ANSWER

What is the two dimensional coordination number of a molecule in square closed packed layer?

Posted by Medha Sherya 7 years, 1 month ago

CBSE > Class 12 > Chemistry

2 answers

Kalas Sahu 7 years, 1 month ago

1Thank You

Sanskriti S 7 years, 1 month ago

1Thank You

ANSWER

What do you mean by buna s

Posted by Mitesh Sharma 7 years, 1 month ago

CBSE > Class 12 > Chemistry

3 answers

Yash Tyagi 7 years, 1 month ago

Buna-S is a condensation polymer having 2 monomeric units which are 1,3-butadiene and styriene

0Thank You

Shivam Bhati 7 years, 1 month ago

Condensetion polymer of buta-1,3-diene and styrene

1Thank You

Sanskriti S 7 years, 1 month ago

addition polymer of buta-1,3-diene & styrene

4Thank You

ANSWER

what is antilog of 18.644

Posted by A B 7 years, 1 month ago

CBSE > Class 12 > Chemistry

1 answers

Sanskriti S 7 years, 1 month ago

4.406*10^18

2Thank You

ANSWER

what is antilog of 18.6444

Posted by A B 7 years, 1 month ago

CBSE > Class 12 > Chemistry

2 answers

Sanskriti S 7 years, 1 month ago

no, log tables are provided and u 've to solve it

2Thank You

Dharshika As 7 years, 1 month ago

such values will be given in paper along with question....and if not given then no need to solve it completely.....just simply write antilog (18.6444) and leave it

0Thank You

ANSWER

Page 234 of 608

myCBSEguide

myCBSEguide

Test Generator

CUET Mock Tests

Download myCBSEguide App

All Courses

Other Websites

CBSE Courses

Resources

Corporate

NCERT Solutions

CBSE Sample Papers