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Ask QuestionPosted by Riya Rana 5 years ago
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Posted by Dev ?? ? 5 years ago
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Gaurav Seth 5 years ago
Entropy is a measure of randomness or disorder of the system.
The greater the randomness, higher is the entropy.
Solid state has the lowest entropy, the gaseous state has the highest entropy and the liquid state has the entropy in between the two.
Entropy is a state function. The change in its value during a process, is called the entropy change.
ΔS = S2 -S1 = ∑S products – ∑S reactants
1) When a system absorbs heat ,the molecules start moving faster because kinetic energy increases. Hence, disorder increases. More the heat absorbed ,greater is the disorder.
2) For the same amount of heat absorbed at low temperature, the disorder is more than at high temperature. This shows that entropy change is inversely proportional to temperature.
ΔS = qrev / T
Posted by Aniket Kasana 5 years ago
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Gaurav Seth 5 years ago
On July 7, HRD Minister Ramesh Pokhriyal announced a major CBSE syllabus reduction with 30% of the syllabus slashed for the year 2020-21 for classes 9 to 12 because of the reduction in classroom teaching time due to the Covid-19 pandemic and lockdown.
CBSE has rationalized the syllabus with the help of suggestions from NCERT and the same has been notified by a new CBSE notification as well.
The CBSE syllabus has been reduced but care has been taken so that the learning outcomes remain the same and the students do not miss out on learning core concepts in various subjects.
Deleted syllabus of CBSE Class 12 Chemistry
Posted by Ngamthuipou Malangmei 5 years ago
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Abhi Panday 5 years ago
Posted by Ngamthuipou Malangmei 5 years ago
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Posted by Jai Karnani 5 years ago
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Jyoti Yadav 4 years, 11 months ago
Abhi Panday 5 years ago
Posted by ☺️Vanshika Baliyan?? 5 years ago
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Lovely Sharma 4 years, 11 months ago
Gourav Sharma 5 years ago
Yogita Ingle 5 years ago
Aromatic carboxylic acids do not undergo Friedal-Crafts reaction because the carboxylic group is strongly deactivating and the catalyst AlCl3AlCl3 (lewis acid ) gets bonded to the carboxylic group strongly
Posted by Jai Karnani 5 years ago
- 3 answers
Gaurav Seth 5 years ago
On July 7, HRD Minister Ramesh Pokhriyal announced a major CBSE syllabus reduction with 30% of the syllabus slashed for the year 2020-21 for classes 9 to 12 because of the reduction in classroom teaching time due to the Covid-19 pandemic and lockdown.
CBSE has rationalized the syllabus with the help of suggestions from NCERT and the same has been notified by a new CBSE notification as well.
The CBSE syllabus has been reduced but care has been taken so that the learning outcomes remain the same and the students do not miss out on learning core concepts in various subjects.
Deleted syllabus of CBSE Class 12 Chemistry
Posted by Ramya Mardi 5 years ago
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Palak Agrahari 5 years ago
Posted by ☺️Vanshika Baliyan?? 5 years ago
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Posted by Himanshi Tripathi 5 years ago
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Nitin Kamboj 5 years ago
Posted by Shivani Sharma 5 years ago
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Posted by .Aks Kumar Singh Daksh Prajapati 5 years ago
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Posted by Deepak Kumar 5 years ago
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Abhi Panday 5 years ago
Posted by Ribal Bitar 5 years ago
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Posted by Anand Singh 5 years ago
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Yogita Ingle 5 years ago
The maximum (or reversible) work that can be done by a thermodynamic system at constant temperature and pressure is known as Gibbs energy. The reversible work in thermodynamics means a special method in which work is carried out such that the system is in perfect equilibrium with all its surroundings.
Posted by Sarika Singh 5 years ago
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Posted by Tannu Jaiswal 5 years ago
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Yogita Ingle 5 years ago
Le Chatelier’s principles, also known as the equilibrium law, are used to predict the effect of some changes on a system in chemical equilibrium (such as the change in temperature or pressure). The principle is named after the French chemist Henry Louis Le Chatelier.
Le Chatelier said that equilibrium adjusts the forward and backward reactions in such a way to accept the changes affecting the equilibrium conditions.
Posted by Ashwani Pratap Singh Lodhi 5 years ago
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Kl? ?? 5 years ago
Posted by Anuj Chahar 5 years ago
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Jassi Midha 4 years, 11 months ago
Yogita Ingle 5 years ago
In an aqueous medium, Cu2+ is more stable than Cu+. This is because although energy is required to remove one electron from Cu+ to Cu2+, high hydration energy of Cu2+ compensates for it. Therefore, Cu+ ion in an aqueous solution is unstable.
Posted by Jai Karnani 5 years ago
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Lovely Sharma 4 years, 11 months ago
Posted by Vidya Vipul 5 years ago
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Gourav Sharma 5 years ago
Yogita Ingle 5 years ago
A Standard Hydrogen Electrode (SHE) is an electrode that scientists use for reference on all half-cell potential reactions. The value of the standard electrode potential is zero, which forms the basis one needs to calculate cell potentials using different electrodes or different concentrations. SHE is composed of a 1.0 M H+(aq) solution containing a square piece of platinized platinum (connected to a platinum wire where electrons can be exchanged) inside a tube.
Posted by Kritika Mehta 5 years ago
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Yogita Ingle 5 years ago
General Methods of Preparation of Alcohols 1. Hydrolysis of Halides
Alkyl halides when boiled with an aqueous solution of an alkali hydroxide give alcohol through nucleophilic substitution mechanism.
R-X + KOH → R-OH + KX
This general procedure produces primary and secondary alcohols. Glycerol can be synthesized from propylene by a series of reactions including the hydrolysis of a halide as one step in the process.
2. Hydration of Alkanes
Direct hydration takes place by adding water in the presence of a catalyst.
Posted by ☺️Vanshika Baliyan?? 5 years ago
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Yogita Ingle 5 years ago
Gabriel phthalimide synthesis is used for preparing only primary amines. Phthalimide is first treated with KOH and then with an alkyl halide to form N-alkyl phthalimide. N-alkyl phthalimide on hydrolysis gives primary amine.
Posted by Muskan Yadav 5 years ago
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Posted by Sunandini Singh 5 years ago
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Aayan Patel 5 years ago
Yogita Ingle 5 years ago
Fluorine does not exhibit any positive oxidation state as it is the most electro-negative element and does not have d orbitals in its valance shell.
Posted by Devil ? 5 years ago
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Posted by Komal Bansal 5 years ago
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Jassi Midha 4 years, 11 months ago
Sneha Bhardwaj 5 years ago
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Yogita Ingle 5 years ago
It is because of the Metal excess defect due to anionic vacancies.
When crystals of KCl are heated in an atmosphere of potassium vapour, the potassium atoms are deposited on the surface of the crystal. The Cl– ions diffuse to the surface of the crystal and combine with K atoms to give KCl. This happens by loss of electron by sodium atoms to form K+ ions. The released electrons diffuse into the crystal and occupy anionic sites. As a result the crystal now has an excess of potassium. The anionic sites occupied by unpaired electrons are called F-centres (for colour centre). They impart violet colour to the crystals of KCl. The colour results by excitation of these electrons when they absorb energy from the visible light falling on the crystals.
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