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Ask QuestionPosted by Aditya Kumar 4 years, 9 months ago
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Posted by Priyanshu Kumar 4 years, 9 months ago
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Ranger King 4 years, 9 months ago
Gaurav Seth 4 years, 9 months ago
(1) When the electron jumps from energy level higher than n=1 ie. n=2,3,4,5,6 ….to n=1 energy level, the group of lines produced is called lyman series. These lines lie in the ultraviolet region.
(2) The group of lines produced when the electron jumps from 3rd, 4th ,5th or any higher energy level to 2nd energy level, is called Balmer series. These lines lie in the visible region.
Posted by Royal Thakur ? 4 years, 9 months ago
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Yogita Ingle 4 years, 9 months ago
In this triple bond is present between carbon atoms (C C bond).The hybridisation is sp and the general formula involved is CnH2n -2.
- The lowest member of alkynes is: simplest compound that is CH CH (ethyne).
- The common name of it is acetylene.
- It has high Bond dissociation energy, as there is triple bond present therefore the energy is high of the order 823 KJ/mol.
- Due to this reason the acetylene is mixed with O2 and the flame is used for welding purpose.
Posted by Royal Thakur ? 4 years, 9 months ago
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Yogita Ingle 4 years, 9 months ago
The structure of the alcohol functional group is R−OH. Aldehyde is the functional group in which one alkyl group is bonded to the carbonyl atom. The structure of the aldehyde functional group is –CHO.
Posted by Jageshwar Prasad Sahu 4 years, 9 months ago
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Yogita Ingle 4 years, 9 months ago
(i) If Kc > 103, products predominates over reactants i.e; if Kc is very large, the reaction proceeds nearly to completion.
(ii) If Kc < 10-3, reactants predominates over products i.e; if Kc is very small, the reaction proceeds rarely.
(iii) If Kc is in the range of 10-3 to 103, appreciable concentration of both reactants and products are present.
Gaurav Seth 4 years, 9 months ago
(i) If Kc > 103, products predominates over reactants i.e; if Kc is very large, the reaction proceeds nearly to completion.
(ii) If Kc < 10-3, reactants predominates over products i.e; if Kc is very small, the reaction proceeds rarely.
(iii) If Kc is in the range of 10-3 to 103, appreciable concentration of both reactants and products are present.
Posted by ?Ritesh Gupta☺️ 4 years, 9 months ago
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Ranger King 4 years, 9 months ago
Gaurav Seth 4 years, 9 months ago
Alkanes
Alkanes are saturated, open chain hydrocarbons containing carbon-carbon single bonds. e.g., methane (CH4), ethane (C4H6) propane (C3H8), etc.
These hydrocarbons are inert under normal conditions [i.e.,do not react with acids. bases and other reagents). Hence, they were earlier known 88 paraffins (Latin : parum-little; affins-affinity)
Alkanes exhibit chain isomensm, position isomerism and conformational isomerism.
Posted by Aadya Singh 4 years, 9 months ago
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Ranger King 4 years, 9 months ago
Posted by Aadya Singh 4 years, 9 months ago
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Priyanshu Kumar 4 years, 9 months ago
Yogita Ingle 4 years, 9 months ago
Diffusion is a phenomenon where there is a movement of one material move from area of high concentration to the area of low concentration. This means particles or molecules spread through medium. For example, if you spray at the one end of the room you would be able to smell at the other end. This is because of diffusion phenomenon.
Ranger King 4 years, 9 months ago
Posted by सत्य सनातन? 4 years, 9 months ago
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Ranger King 4 years, 9 months ago
Gaurav Seth 4 years, 9 months ago
molecular formula of methane = CH4
we know,
atomic mass of C = 12 g/mol
atomic mass of H = 1 g/mol
so,
molecular mass of CH4 =( 12 + 4 × 1 ) g/mol = 16 g/mol
also we know,
no of molecule = {given weight /molecular weight } × 6.023 × 10²³
here,
given weight = 16 g
molecular weight = 16 g/mol
so,
no of molecules = ( 16/16) × 6.023 × 10²³
= 6.023 × 10²³
Posted by Aadya Singh 4 years, 9 months ago
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Posted by Aadya Singh 4 years, 9 months ago
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Aadya Singh 4 years, 9 months ago
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First Name 4 years, 9 months ago
Posted by Ayush Kashyap 4 years, 9 months ago
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Gaurav Seth 4 years, 9 months ago
Enthalpy is the measurement of energy in a thermodynamic system. The quantity of enthalpy equals to the total content of heat of a system, equivalent to the system’s internal energy plus the product of volume and pressure.
Posted by Aakriti Rustagi 4 years, 9 months ago
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Silêñť Kñighť 4 years, 9 months ago
Posted by Siddharth .(.$Id) 4 years, 9 months ago
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First Name 4 years, 9 months ago
Yogita Ingle 4 years, 9 months ago
We can explain the paramagnetic nature of oxygen molecule by molecular orbital theory.
When you draw molecular orbital diagram of O2
we can see there are two unpaired electrons are present in the last molecular orbital which shows us that it is paramagnetic in nature.
Posted by Sandeep Kaur 4 years, 9 months ago
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Sakshi Chouhan 4 years, 9 months ago
Posted by Krishna Agrawal 4 years, 9 months ago
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Gaurav Seth 4 years, 9 months ago
Among molecule the energy required to break the first N-H bond and other N-H bond is not same" is true.
The reason for this is -
- Dissociation energy for the
bond of
that is of N-H and
species gets decreased in its value.
- This means that the breaking of first N-H bond of ammonia molecule during dissociation requires more energy or the highest energy among all the further dissociation.
Posted by Sandeep Kaur 4 years, 9 months ago
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Posted by Sachi Chauhan 4 years, 9 months ago
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Gaurav Seth 4 years, 9 months ago
Enthalpy of vaporization is the amount of energy that must be supplied to the liquid in order to change the liquid into a gas. Enthalpy is also regarded as boiling temperature of the liquid.
Acetone does not have hydrogen bond, and thus intermolecular forces are comparatively weaker which makes it boil/evaporates fast, thus reducing the molar enthalpy of vaporization. Also, Acetone does not polar O-H bond contributing to low enthalpy.
Water has non-polar region and also has strong hydrogen bond. Water has highly polar O-H bond which makes water boil at relatively higher temperature than Acetone thus has enthalpy greater than that of Acetone.
Posted by Pk✍️ . 4 years, 9 months ago
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Mahvish Khan 4 years, 9 months ago
Dεερακ Ȿιηɠꜧ 4 years, 9 months ago
☻☻To bas padhai karte rahe, All the very best ☻☻
Posted by Ankush Jangra 4 years, 9 months ago
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Ranger King 4 years, 9 months ago
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Gaurav Seth 4 years, 9 months ago
He examined the relationship between atomic weights of the elements and their physical and chemical properties.Among chemical properties, Mendeleev mainly concentrated on the compounds formed by the elements with hydrogen and oxygen because they are highly reactive and hence formed compounds with almost all the elements.
The formulae of the hydrides and oxides formed by the various elements was made the basis of classification of elements.
Mendeleev in 1869, proposed periodic law.
It states that
The physical and chemical properties of elements are a periodic function of their atomic weights i.e. when the elements are arranged in order of their increasing atomic weight, elements with similar properties are repeated after certain regular intervals. This repetition of properties of elements after certain regular intervals is called periodicity of properties.
Characteristics of Mendeleev’s periodic table
1)Mendeleev’s arranged the then known elements in order of their increasing atomic weights, grouping together elements with similar properties and leaving out blank space wherever necessary.
2)He also made the prediction that there were some unknown elements which, would be discovered in due course of time and would fill these blank spaces.
3)He predicted their properties in the light of the properties of the other elements in the same group. Later on, these unknown elements were discovered and were found to possess exactly the same properties as predicted by Mendeleev.
4)Noble gases were not known at the time of Mendeleev. When these gases were discovered, a new group called the zero group was added toMendeleev original periodic table.
5)Two group of 14 elements each, called lanthanides and actinides were placed at the bottom of the periodic table.
6)Mendeleev’s periodic table consists of :
periodsa) 9 vertical columns called groups. These are designated as 0, 
, 
, 
, 
,
, 
, 
, 
b) Except for group 0 and ,each group is further divided into two subgroup designated as A and B.The elements which lie on the left hand side of each group constitutes sub-group A while those placed on the right hand side from sub-group B.This subdivision is made on the basis of the differences in their properties.
c)Group contains 9 elements in three sets each containing three elements. Group 0 has no subgroup. It consists of only one vertical column of inert gases.
d)7 horizontal rows called periods.These are numbered from 1 to 7.
Posted by Sony Chauhan 4 years, 9 months ago
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Sachi Chauhan 4 years, 9 months ago
Yogita Ingle 4 years, 9 months ago
DISCOVERY OF ELECTRON:
The Electron was discovered by J.J Thomson by conducting a Cathode ray tube experiment.
For the experiment he used Crooke’s tube, which was 60cm long glass tube and had a small tube attached. To this small tube vacuum pump was attached, it also had two metal plates which were connected to battery by wires.
The tube contained gas at atmospheric pressure. when current at high voltage (10,000volts) was passed following observations were made:
- When current was passed through a gas at 1 atmospheric pressure and at a very high voltage, nothing happened. That is no visible effect was seen inside the tube.
- Then further the pressure of gas was reduced by pumping the air out, with the help of vacuum pump. The pressure was reduced to 10-2atm, then on passing current it was seen that whole tube started glowing green.
Then further the pressure was reduced to 10-4It was seen the whole glow vanished, but it was seen that at the end of the tube (anode side) there was a faint green glow observed.
To confirm the faint glow anode was made perforated, and a zinc sulphide screen (fluorescent material) was placed behind it.
When current was passed under same conditions it also started glowing green. This confirmed that under those conditions some rays were emitted through cathode, and were travelling towards anode. Those rays were called as cathode rays and found to consist of negatively charged particles called electron.
Posted by Aman Soni 4 years, 9 months ago
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Yogita Ingle 4 years, 9 months ago
Since the line in Hydrogen spectrum lies within region that is at Red end.
Therefore it is corresponds to the Balmer series.
The line at the Red end suggests that :-
The 1st line of Balmer series is => n=3 to n=2
The 2nd line of Balmer series is => n=4 to n=2
The 3rd line of Balmer series is => n=5 to n=2
Thus the answer is => 5 --> 2 = 5 to 2
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Gaurav Seth 4 years, 9 months ago
The goal of alchemy was to find a mythical and magical substance called “philosopher’s stone” not a literal stone but wax, liquid or powder with magical power, which on heating with a base, iron and copper metals would turn into gold, the purest form of matter which would bring wealth, health and immortality.
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