Asked/Added Questions From NCERT: Chemistry

nisha sheikh
Temperature of gases changes only when internal energy of the gases changes. Temperature of the gas is related to du by du = nCvΔT. Hence for all those infinite possible values of du, you will have infinite possible temperatures, still maintaining constant net heat of the system . i.e dq as zero.

-Answered by nisha sheikh On 21 October 2020:06:50:47 PM

Shruti Srivastva
An ice box is made of double wall and the space between the walls is filled with some non-conducting material to provide heat insulators, so that the loss of heat can be minimised.

-Answered by Shruti Srivastva On 03 October 2020:05:27:03 PM

Shruti Srivastva
Due to smaller size of F than Cl as a result of which electron-electron repulsions between the lone pairs of electrons are very large than that of Cl, hence bond dissociation energy of F₂ is less than that of Cl₂.

-Answered by Shruti Srivastva On 12 September 2020:05:55:10 PM

Shruti Srivastva
Lower the melting point of the mixture and brings conductivity. 

-Answered by Shruti Srivastva On 12 September 2020:05:52:37 PM

Shruti Srivastva
Buna-S, Buna-N.

-Answered by Shruti Srivastva On 12 September 2020:05:50:54 PM

Rohit Rajput

-Answered by Rohit Rajput On 26 September 2020:07:19:07 PM

Shruti Srivastva
The stability of the +5 oxidant state decreases and that of +3 state increases due to the inert pair effect down the group therefore Bi accepts two electrons and get reduced to Bi. 

-Answered by Shruti Srivastva On 12 September 2020:05:46:50 PM

Shruti Srivastva
Because the method is based on preferential wetting properties with the frothing agent and water, and the suphide particles of res stick to the oil droplets and rise in the form of forth. 

-Answered by Shruti Srivastva On 12 September 2020:05:43:21 PM

nisha sheikh
Tyndall effect, also called Tyndall phenomenon, scattering of a beam of light by a medium containing small suspended particles—e.g., smoke or dust in a room, which makes visible a light beam entering a window.

-Answered by nisha sheikh On 20 September 2020:06:57:34 PM

Shruti Srivastva
Frenkel defect. 

-Answered by Shruti Srivastva On 12 September 2020:05:40:59 PM

Shruti Srivastva
Alertness. 

-Answered by Shruti Srivastva On 11 September 2020:05:46:36 PM

Shruti Srivastva
Keeping a wet hankerchief in our mouth. 

-Answered by Shruti Srivastva On 11 September 2020:05:43:06 PM

Shruti Srivastva
Safety of small childrens. 

-Answered by Shruti Srivastva On 11 September 2020:05:37:46 PM

Shruti Srivastva
Small children generally put the toys in their mouth while playing with them . 

-Answered by Shruti Srivastva On 11 September 2020:05:33:28 PM

Shruti Srivastva
Lead (pb). 

-Answered by Shruti Srivastva On 11 September 2020:05:32:02 PM

Shruti Srivastva
Safety and security.

-Answered by Shruti Srivastva On 11 September 2020:05:30:04 PM

Shruti Srivastva
He doesn't know that water should not be added to conc. 

-Answered by Shruti Srivastva On 11 September 2020:05:27:52 PM

Rohit Rajput
Osmotic pressure is the measure of excess presure applied on solution side to stop the process od osmotic. Osmotic pressure is directly proportional to the concentration off solute in the solution.

  

-Answered by Rohit Rajput On 10 September 2020:11:23:48 AM

Rohit Rajput
(i) Frenkel defect- The defect in which the smaller ion/cation is dislocated to a nearby interstitial site.

Ex- Silver halides, ZnS.

(ii) F-centres- The aninon vacancy occupied by an electrons is called F-centres in Alkali metal halides.

Ex- NaCL, KCL, LiCL.

-Answered by Rohit Rajput On 10 September 2020:11:26:17 AM

Rohit Rajput
Colloids which acts as electrolyte at low concentration and show colloidal behaviour at high concentration are called Associated colloids.

Ex- Soap solution and detergents.

-Answered by Rohit Rajput On 10 September 2020:11:09:12 AM

Rohit Rajput
It is true to large size of colloidal particles. In colloidal solution particle size of dispersed phase is comparable to the wavelength of light used.

-Answered by Rohit Rajput On 10 September 2020:11:11:57 AM

Rohit Rajput
Rate constant: It is defined as the rate of reaction when the concentration of reactants is taken as unity.

-Answered by Rohit Rajput On 10 September 2020:11:15:09 AM

Shruti Srivastva
(i) Fair dealing

(ii) Business ethics.

(iii) Selling a non-standardized products with the help of false advertisements. 

-Answered by Shruti Srivastva On 28 August 2020:05:30:26 PM

Shruti Srivastva
Groundwater is hard water and it contains Ca⁺² and Mg⁺² salts which react with soap produce a curdy precipitate that adheres to the fabric as gummy mass and blocks the ability of soap to remove dirt.

-Answered by Shruti Srivastva On 28 August 2020:05:27:30 PM

Shruti Srivastva
We have to inform the concerned authority about the excess of CO in the coal mine. 

-Answered by Shruti Srivastva On 28 August 2020:05:21:19 PM

Shruti Srivastva
By using I₂O₅.

-Answered by Shruti Srivastva On 28 August 2020:05:19:09 PM

Shruti Srivastva
In coal mines to lack of oxygen, a small percentage of carbon monoxide is formed. 

-Answered by Shruti Srivastva On 27 August 2020:06:03:37 PM

Shruti Srivastva

Cadmium plate battery through expensive is not as strong a pollutant as a lead. Lead salt beings insoluble in water if ingested into our system cannot be excreted out. Whereas Cd and Ni salts are water-soluble. therefor get biomagnified in the body. 

-Answered by Shruti Srivastva On 27 August 2020:05:52:27 PM

Shruti Srivastva
The industry is ignoring its social responsibility for the health and safety of people and respect for the environment. Due to water and air pollution caused by the industry, the entire ecological system will collapse. 

-Answered by Shruti Srivastva On 27 August 2020:05:46:25 PM

Shruti Srivastva
(i) Lack of safety and security.

(ii) Lack of value for human life. 

(iii) Lack of responsibility towards their own amilies and society at large. 

-Answered by Shruti Srivastva On 25 August 2020:05:35:37 PM

Shruti Srivastva

Gas masks containing activated charcoal are frequently used by miners. Poisonous gases like CH₄, CO etc. can be selectively absorbed by the gas masks containing activated charcoal. 

-Answered by Shruti Srivastva On 25 August 2020:05:32:39 PM

Anjali Kumari

-Answered by Anjali Kumari On 12 October 2020:07:24:21 PM

Shruti Srivastva
Gas mask containing activated charcoal are frequently used by miners. Poisonous gases like CH_4, CO, etc. can be selectively absorbed by the gas mask containing activated charcoal. 

-Answered by Shruti Srivastva On 24 August 2020:05:51:22 PM

Shruti Srivastva
Lipid and Protiens.

-Answered by Shruti Srivastva On 24 August 2020:05:48:57 PM

Shruti Srivastva

 0.2% solution of phenol acts as antiseptic whereas 1 % solution o phenol acts as disinfectant. 

-Answered by Shruti Srivastva On 24 August 2020:05:46:50 PM

Shruti Srivastva
Phenacetin is an antipyretic, while the rest are tranquilizers. 

-Answered by Shruti Srivastva On 24 August 2020:05:43:40 PM

Shruti Srivastva
Fe exists as Fe²⁺.There are 4 unpaired electrons. Water is weak ligand. Thus the hybridisation involved is sp³d². It is an octahedral outer d-orbital complex. 

-Answered by Shruti Srivastva On 24 August 2020:04:56:36 PM

Shruti Srivastva

At high pressure, amount of gas absorbed (x/m) becomes independent of pressure (P). 

-Answered by Shruti Srivastva On 24 August 2020:04:47:48 PM

Shruti Srivastva
(i) Same charge on all the colloidal particles.

(ii) Solvation of the colloidal particle. 

-Answered by Shruti Srivastva On 24 August 2020:04:45:39 PM

Shruti Srivastva
A reddish brown coloured solution is obtained. 

-Answered by Shruti Srivastva On 24 August 2020:04:43:43 PM

Shruti Srivastva

1-Methylcyclohexene

-Answered by Shruti Srivastva On 24 August 2020:04:40:51 PM

Shruti Srivastva
 BiH₃,< SbH₃ < AsH₃< PH₂< NH₃

-Answered by Shruti Srivastva On 24 August 2020:04:37:26 PM

Shruti Srivastva
L₂<F₂<Br₂<Cl₂

-Answered by Shruti Srivastva On 24 August 2020:04:32:09 PM

Shruti Srivastva
Chromite ore. 

-Answered by Shruti Srivastva On 24 August 2020:04:29:27 PM

Shruti Srivastva
Cerium (Ce). 

-Answered by Shruti Srivastva On 24 August 2020:04:28:10 PM

Shruti Srivastva
KMnO₄.

-Answered by Shruti Srivastva On 24 August 2020:04:26:31 PM

Shruti Srivastva
Scandium (Sc)

-Answered by Shruti Srivastva On 24 August 2020:04:21:00 PM

Shruti Srivastva
Three ions [Co(NH₃)₆]²⁺,2Cl^-

-Answered by Shruti Srivastva On 24 August 2020:04:17:42 PM

Shruti Srivastva
Neopentate or 2, 2-Dimethylpropane. 

-Answered by Shruti Srivastva On 24 August 2020:04:15:27 PM

Shruti Srivastva
Catalysis by zeolites which depends on the shape and size of the reactants and the products as compared to those of the pores and cavities of zeolites. 

-Answered by Shruti Srivastva On 24 August 2020:04:11:23 PM

Shruti Srivastva
Metal excess or anionic vacancies or F-centres. 

-Answered by Shruti Srivastva On 24 August 2020:04:10:02 PM

Shruti Srivastva
The component of the solution that dissolves the other component in it is called the solvent. 

-Answered by Shruti Srivastva On 19 August 2020:06:02:32 PM

Shruti Srivastva
Mixtures are constituted by more than one kind of pure form of matter. 

-Answered by Shruti Srivastva On 19 August 2020:06:00:47 PM

Shruti Srivastva
Depending upon the amount of solute present in a solution, it can be called a dilute. 

-Answered by Shruti Srivastva On 19 August 2020:05:58:49 PM

Shruti Srivastva
If the amount of solute contained in a solution is less than the saturated level, it is called an unsaturated solution. 

-Answered by Shruti Srivastva On 19 August 2020:05:57:07 PM

Shruti Srivastva
The amount of solute present in the saturated solution at this temperature is called its solubility. 

-Answered by Shruti Srivastva On 19 August 2020:05:55:23 PM

Shruti Srivastva
When no more solute can be dissolved in a solution at a given temperature, it is called a saturated solution. 

-Answered by Shruti Srivastva On 19 August 2020:05:54:02 PM

Shruti Srivastva
It has a non- uniform composition.

-Answered by Shruti Srivastva On 19 August 2020:05:52:51 PM

Shruti Srivastva
Because volume of ice is more than water. 

-Answered by Shruti Srivastva On 19 August 2020:05:47:19 PM

Rohit Rajput

-Answered by Rohit Rajput On 26 September 2020:07:23:14 PM

Shruti Srivastva
303 K. 

-Answered by Shruti Srivastva On 19 August 2020:05:44:06 PM

Rohit Rajput

 Shimla have higher altitude than Delhi. And Shimla have low atmospheric pressure. And The boiling Point is low on lower atmospheric pressure. ... Hence, the boiling point of water is lower in Shimla than in Delhi.

-Answered by Rohit Rajput On 26 September 2020:07:24:11 PM

Shruti Srivastva
For preservation.

-Answered by Shruti Srivastva On 19 August 2020:05:41:27 PM

Shruti Srivastva
Dry ice. 

-Answered by Shruti Srivastva On 19 August 2020:05:40:42 PM

Shruti Srivastva
The force attraction between the particles. 

-Answered by Shruti Srivastva On 19 August 2020:05:39:09 PM

Shruti Srivastva
It is faster in the summer. 

-Answered by Shruti Srivastva On 19 August 2020:05:37:24 PM

Shruti Srivastva

 Parabolic path.

-Answered by Shruti Srivastva On 11 July 2020:12:33:50 PM

Shruti Srivastva

 1 parasec= 3.08 X 10¹⁶m

-Answered by Shruti Srivastva On 07 July 2020:04:38:51 PM

Aman Senapati

 It can be defined as a condition in which normal functioning of the body or its some part or organ is disturbed or deranged.

-Answered by Aman Senapati On 26 June 2020:07:41:00 AM

Aman Senapati

 Physical Health:- It refers to the normal state of structure and functioning of various body organ.Physical Health can be determined by several medical tests and physical examination.

Mental Health:- It is associated with the mental satisfaction of a person.It maintains a balance and harmony between individual's expectation and achievement.It is difficult to measure

Social Health:- It implies social well being,i.e.,good relation and happiness at home , at working place and with neighbours and friends.Social health is still more difficult to assess.

-Answered by Aman Senapati On 26 June 2020:07:26:31 AM

Aman Senapati

 Development of immunity or body resistance against a pathogen through vaccination is called immunisation.

-Answered by Aman Senapati On 24 June 2020:10:20:58 AM

Aman Senapati

 We are advised to take bland and nourishing food when we are sick so as to :-

a)Provide nourishment to body , to recover from weakness.

b)Strength our body's immune system.

-Answered by Aman Senapati On 24 June 2020:08:38:27 AM

Aman Senapati

 a)Hygienic living conditions and perfect personal hygiene.

 b)Balanced diet, clean drinking water, adequate physical exercise.

-Answered by Aman Senapati On 24 June 2020:08:21:44 AM

Aman Senapati

 a)Complete physical fitness, i.e.,free from any disease.

 b)Perfect mental and social well-being.

-Answered by Aman Senapati On 24 June 2020:08:19:15 AM

Master Purushottam

Solid id one of the four fundamental states of matter (the other being liquid, gas and plasma). The atoms in a solid are closed packed together and contain the least amount of kinetic energy. A solid is characterized by structural rigidity and resistance to a force applied to the surface.

  

-Answered by Master Purushottam On 31 May 2020:12:14:13 AM

Master Purushottam

 The fourth state of matter is Plasma , Plasma is a hot ionized gas consisting of approximately equal numbers of positively charged ionsand negatively charged electrons. The fifth state of matter is BEC(Bose-Einstein Consensate). 

-Answered by Master Purushottam On 31 May 2020:12:18:00 AM

Master Purushottam

 The particles of matter are very, very small. The particles of matter have space between them. The particles of matter are constantly moving. The particles of matter attracted each other.

-Answered by Master Purushottam On 31 May 2020:12:20:50 AM

Master Purushottam

Intermixing of particles of different matter in spaces between particles is known as Diffusion.  

-Answered by Master Purushottam On 31 May 2020:12:22:55 AM

Master Purushottam

 The erratic random movement of microscope particles in a fluid, as a result of continuous bombardment From molecules of the surrounding medium.

   

-Answered by Master Purushottam On 31 May 2020:12:24:35 AM

Himanshi Verma

 This law was proposed by Dalton in 1803. According to this law if two elements can combine to form more than one compounds, the masses of one element that combined with a fixed mass of the other element are in the ratio of small whole numbers.

-Answered by Himanshi Verma On 27 May 2020:03:17:53 PM

Nishant Verma

 The movement of atoms or morecules for an area of higher concentration to an area of lower Concentration. Some substances like carbon-di-oxide  or oxygen can move across cell membrane from region of high concentration to a region where concentration is low this process is known as diffusion.

-Answered by Nishant Verma On 27 May 2020:09:59:40 AM

Nishant Verma

 Cohesive ( from Latin cohaesio  "cling or unit"). Or cohesive attraction or cohesive force is the action or property of like molecules to sticking together, being a mutually attrative.

-Answered by Nishant Verma On 27 May 2020:09:40:45 AM

Aman Senapati

1. How small are the particles of matter.
2. The particles of matter have space between them .
3. The particles of matter attract each other.
4. The particles of matter are in continuous motion.

-Answered by Aman Senapati On 27 May 2020:09:27:30 AM

Aman Senapati

 A drop of water has about 1,00,00,00,00,00,00,00,00,00,000 particles(molecules).

-Answered by Aman Senapati On 27 May 2020:09:19:17 AM

Aman Senapati

 The five elements are:-

1. Akasha(sky)
2. Vayu(air)
3. Kshiti(earth)
4. Jal(water)
5. Pawak(fire)

-Answered by Aman Senapati On 26 May 2020:07:43:31 AM

Aman Senapati

 An Atom is an smallest component of an elements,characterized by a sharing of the chemical properties of the element and a nucleus with neutrons,protons and electrons.

-Answered by Aman Senapati On 26 May 2020:07:46:33 AM

Aman Senapati

1.  Earth 
2.  Air 
3.  Water
4.  Fire

-Answered by Aman Senapati On 26 May 2020:07:51:13 AM

Aman Senapati

 Greek philosophers Empedocles.

-Answered by Aman Senapati On 26 May 2020:07:52:41 AM

Aman Senapati

 The following are not considered matter:-

1. Types of energy like heat,light etc.
2. Sensation
3. Emotions:love,hatred,affection,friendship,etc.
4. Time

-Answered by Aman Senapati On 26 May 2020:07:56:41 AM

Aman Senapati

 Mass is the amount of matter present in an objects.

-Answered by Aman Senapati On 25 May 2020:07:28:04 PM

Aman Senapati
Anything that has mass and occupies space (i.e has volume)is called Matter.

-Answered by Aman Senapati On 25 May 2020:07:24:14 PM

Suraj Kumar
Do it Yourself

-Answered by Suraj Kumar On 10 November 2019:03:52:38 PM

priyanshu kumar

 Uttarakhand

-Answered by priyanshu kumar On 03 October 2019:12:34:18 PM

priyanshu kumar
Crystallization of table salt from sea water

-Answered by priyanshu kumar On 03 October 2019:12:34:52 PM

priyanshu kumar

 Selenium.

-Answered by priyanshu kumar On 03 October 2019:12:35:01 PM

priyanshu kumar
George Washington.

-Answered by priyanshu kumar On 20 October 2019:09:51:45 AM

Harshita Rathore
Benjamin Franklin

-Answered by Harshita Rathore On 02 September 2019:01:51:03 PM

Shivang Gupta
 Barbadian dollar. 

-Answered by Shivang Gupta On 25 August 2019:02:45:12 PM

Akki chauhan

 Trivantepuram.

-Answered by Akki chauhan On 24 August 2019:02:46:41 PM

Akki chauhan

 Archery.

-Answered by Akki chauhan On 24 August 2019:11:11:52 AM

priyanshu kumar

 Berlin.

-Answered by priyanshu kumar On 10 November 2019:03:26:19 PM

Himanshi Verma
The common name of POP(Plaster of Paris) is Calcium sulphate hemihydrate.

It uses are:-

1. Its used for supporting fractured bones.

2. It is used for making sufaces smooth.

3. It is used in many material and making in toys.

4. It is used for making statues.

-Answered by Himanshi Verma On 21 August 2019:05:15:13 PM

Himanshi Verma

 The formula of washing soda is Na₂Co₃.10H₂o. Recrystallisation of sodium carbonate gives  washing soda. It is a basic salt.

Its uses are:-

1. It is used in glass, soap and paper industries.

2. It is used in manufacture of Borax.

3. It is used as cleaning agent for domestic purpose.

4. It is used for removing permanent hardness of water.

-Answered by Himanshi Verma On 21 August 2019:04:56:37 PM

Himanshi Verma

 When electricity is passed through an aqueous solution of sodium chloride it decomposes to form sodium hydroxide. The process is called the chlor-alkali alkali process because of the products formed: chlor for chlorine and alkali for Sodium Hydroxide. Chlorine gas is given off at the anode and hydrogen gas at the cathode.

An aqueous solution of sodium chloride is called brine.
2NaCl (aq) + 2H2O(l) ---(electrolysis)---> 2NaOH(aq) + Cl2(g) + H2(g).

-Answered by Himanshi Verma On 21 August 2019:04:54:18 PM

Himanshi Verma

 Methanoic acid is present in ant sting.

-Answered by Himanshi Verma On 21 August 2019:04:52:47 PM

Himanshi Verma

 The compunds formed by the transfer of electrons from a metal to a non- metal are called ionic compounds or electrovalent compounds.

-Answered by Himanshi Verma On 21 August 2019:04:50:17 PM

Himanshi Verma

 Carbon has 4 electrons in its outer most orbits and in order to attain the noble gas configuration it should either lose the 4 electrons and gain helium gas configuration or gain 4 electrons to obtain neon gas configuration

But is very difficult for it to gain or lose 4 electrons as very high energy is required to remove 3rd or 4th electrons and also it's very difficult for it to gain 4 electrons and hold it.
Hence carbon atom undergoes covalent bonding with other atoms to become stable. 

-Answered by Himanshi Verma On 21 August 2019:04:48:24 PM

Himanshi Verma

 1. Position of isotopes could not be explained.

2. No fixed position for hydrogen.

3. Wrong order of atomic masses of some elements could not be explained.

-Answered by Himanshi Verma On 21 August 2019:04:44:39 PM

Himanshi Verma

 The carbonate ores are changed into oxides by heating strongly in limited air. This process is called Calcination.

-Answered by Himanshi Verma On 21 August 2019:04:32:51 PM

Himanshi Verma

 1. No, fixed position can be given to hydrogen in the Mendeleev's classification.

2. There are no any place for isotopes.

3. It was not possible to predict how many elements could be discovered between two elements.  

-Answered by Himanshi Verma On 20 August 2019:07:44:51 PM

Himanshi Verma

 Silicon dioxide.

-Answered by Himanshi Verma On 19 August 2019:10:56:21 PM

Himanshi Verma

 Father of Antoine Lavoisier is "Jean Antoinie Lavoisier".

-Answered by Himanshi Verma On 01 July 2019:07:27:27 PM

Akki chauhan

 vitamin C

-Answered by Akki chauhan On 05 February 2019:09:57:59 AM

Akki chauhan

 Toxin

-Answered by Akki chauhan On 05 February 2019:09:57:55 AM

Akki chauhan

 Sulphur

-Answered by Akki chauhan On 05 February 2019:09:57:50 AM

Master Purushottam
By the process of sublimation

-Answered by Master Purushottam On 24 August 2019:12:02:19 AM

Master Purushottam
In U.S.A

-Answered by Master Purushottam On 23 August 2019:11:50:20 PM