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Daltins atomic theory_ he said that matter consist of indivisible atoms Atoms of same element having same and identical properties but different to the atom of another elements Compounds are formed when the atoms of different element combine in fixed ratio Chemical reaction involves the reorganization of atoms. I n every chemical reaction atoms do not loose their identity

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Law of definite proportion

Posted by Mou Saha 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Shubham Bhardwaj 8 years, 3 months ago

Just get lost

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Agni Roy 8 years, 3 months ago

The law of definite proportions, also known law of definite composition, states that regardless of the amount, a pure compound always contains the same elements in the same proportions by mass. Law of multiple proportions, also known as Dalton s Law, states that when one element combines with another to form more than one compound, the mass rations of the elements in the compounds are simple whole numbers of each other.

LAW OF DEFINITION PROPORTIONS EXAMPLE
The law of definite proportions says water will always contain 1/9 hydrogen and 8/9 oxygen by mass.

EXCEPTIONS TO THE LAW OF DEFINITE PROPORTIONS
Although the law of definite proportions is useful in chemistry, there are exceptions to the rule. Some compounds are non-stoichiometric in nature, meaning their elemental composition varies from one sample to another. For example, wustite is a type of iron oxide with an elemental composition varying between 0.83 and 0.95 iron atoms for each oxygen atom (23%-25% oxygen by mass). It ideal formula is FeO, but the crystal structure is such that there are variations. The formula is written Fe0.95O.

Also, isotopic composition of an element sample varies according to its source. This means the mass of a pure stoichiometric compound will be slightly different depending on its origin.

Polymers also vary in element composition by mass, although they are not considered true chemical compounds in the strictest chemical sense.

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Assign position of element having outer electronic configuration ns2np4 for n equals 3

Posted by Shailendra Bholu 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Anantha Krishnan 8 years, 3 months ago

Sulphur

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Define Schrodinger's equation

Posted by Priyanshu Singh 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Shailendra Bholu 8 years, 3 months ago

It is that equation on solving which we get total energy and wave function(psi) .and wave function are used to express atomic orbital.but when we talk about it's definition it is nothing but a mathematical eqation which describes the wave motion of electron in 3d space around nucleus.

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Which compound have highest polarization effect LiCl,BeCl2,BCl3

Posted by Ashish Ohlyan 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Priyanshu Singh 8 years, 3 months ago

Becl3

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Does photoelectric effect obeys law of conservation?

Posted by Shivam Dwivedi 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Shailendra Bholu 8 years, 3 months ago

Yes

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Shivam Dwivedi 8 years, 3 months ago

Yes, the total momentum and energy is conserved during this phenomenon, but... There is an interesting thing, during the process old photons brusts of and new photons are generated.

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Define photoelectric effect

Posted by Khushboo Bansal 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Vandana Amol 8 years, 3 months ago

The phenomenon of ejection of electrons from the metal surface when light of suitable frequency strike on it, is called photoelectric effect.

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Khushboo Bansal 8 years, 3 months ago

When a light of certain frequency is incident on a metal surface . Then electrons are emitted from metal surface . The emitted electrons are known as photoelectrons and this phenomena is known as photoelectric effect

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What is molecular mass?

Posted by Adii Tyagi 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Shivam Dwivedi 8 years, 3 months ago

Sum of atomic masses of all individual atoms in molecule of the compound, is molecular mass of that compound.

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Amar Kumar 8 years, 3 months ago

Molecular mass or molecular weight is the mass of a molecule. It is calculated as the sum of the atomic weights of each constituent element multiplied by the number of atoms of that element in the molecular formula.

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What is hybrid orbitals

Posted by Istiyaq Ahmad 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Shivam Dwivedi 8 years, 3 months ago

The process of intermixing of atomic orbitals, to form new orbitals having equal energy and shape is called hybridization. And new orbitals formed are called hybrid orbitals.

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Faijan rule

Posted by Istiyaq Ahmad 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Ayush Meena 8 years, 3 months ago

The covalent character in ionic bond is determined by Fajans rule

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Ideol equation

Posted by Pradeep Prajapat 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Vandana Amol 8 years, 3 months ago

PV:- nRT

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Ideal equation

Posted by Pradeep Prajapat 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Swarnali Mondal 8 years, 3 months ago

Ideal Gas Equation Is PV = nRT.

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Name two chemical compound is used in treatment of cancer

Posted by Tulika Srivastawa 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Amar Kumar 4 years, 2 months ago

Topothecan and Cisplatin

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Non medi

Posted by Gagan Rai 8 years, 3 months ago

CBSE > Class 11 > Chemistry

0 answers

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Why does ice floats on water

Posted by Gagan Rai 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Vijay Arora 8 years, 3 months ago

When ice is formed a cage like structure forms with empty space due to which volume increases and density decreses. As density of ice is less than that of water therefore ice floats.

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What is chemistry

Posted by Atishay Jain 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Shivam Dwivedi 8 years, 3 months ago

"Chemistry is nothing but chemistry behind it." It's a branch of science that efforts to understand relation between different compound and its constituents. It study about how things are made.(unlike physics which study about how things works).

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Amar Kumar 8 years, 3 months ago

Chemistry is the branch of science concerned with the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances.

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What is polyatomic

Posted by Vinay Kumar 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Amar Kumar 8 years, 3 months ago

A polyatomic ion, also known as a molecular ion, is a charged chemical species (ion) composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit, ions of two atoms are commonly referred to as polyatomic.

An example of a polyatomic ion is the hydroxide ion; consisting of one oxygen atom and one hydrogen atom, hydroxide has a charge of −1. Its chemical formula is OH⁻. Polyatomic ions are often useful in the context of acid-base chemistry or in the formation of salts.

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What is diatomic molecule

Posted by Vinay Kartik 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Amar Kumar 8 years, 3 months ago

Diatomic molecules are molecules composed of only two atoms, of the same or different chemical elements. The prefix di- is of Greek origin, meaning "two".

There are seven elements that naturally occur as homonuclear diatomic molecules in their gaseous states: hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine.

If the diatomic molecule consists of atoms from two different elements, then it is a heteronuclear diatomic molecule.

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In 3 moles of ethane (c2H6) calculate the following : Number of molecules of ethane

Posted by Palak Sharma 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Pnp Jain 8 years, 3 months ago

No. of moles= 3 No. of molecules of ethane in 1mole=6.022*10²³ Therefore, no. of molecules of ethane in 3 moles =6.022 * 10²³ * 3moles =18.066 * 10²³ =1.8066 * 10²⁴

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What is atomic radii

Posted by Dishank Shrivastava 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Shreya Verma 8 years, 3 months ago

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definitions of atomic radius are: Van der Waals radius, ionic radius, and covalent radius. Depending on the definition, the term may apply only to isolated atoms, or also to atoms in condensed matter, covalently bound in molecules, or in ionized and excited states; and its value may be obtained through experimental measurements, or computed from theoretical models. The value of the radius may depend on the atom's state and context.[1] Electrons do not have definite orbits, or sharply defined ranges. Rather, their positions must be described as probability distributions that taper off gradually as one moves away from the nucleus, without a sharp cutoff. Moreover, in condensed matter and molecules, the electron clouds of the atoms usually overlap to some extent, and some of the electrons may roam over a large region encompassing two or more atoms. Under most definitions the radii of isolated neutral atoms range between 30 and 300 pm (trillionths of a meter), or between 0.3 and 3 ångströms. Therefore, the radius of an atom is more than 10,000 times the radius of its nucleus (1–10 fm),[2] and less than 1/1000 of the wavelength of visible ligh

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What are the short comings of Wurtz reaction???...

Posted by Annu Sehrawat 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Abhay Verma 7 years, 10 months ago

yes my friend

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Amar Kumar 8 years, 3 months ago

The Wurtz reaction is limited to the synthesis of symmetric alkanes. If two dissimilar alkyl halides are taken as reactants, then the product is a mixture of alkanes that is, often, difficult to separate as the difference in boiling point would be very low in these cases therefore distillation wouldn't work.

Also, since the reaction involves free radical species, a side reaction occurs to produce an alkene. This side-reaction becomes more significant when the alkyl halides are bulky at the halogen-attached carbon. This is because the activation energy required becomes significantly high, so the alternate elimination mechanism is favoured. That's why you should only use primary alkyl halides for the reaction. otherwise use a reagent in which the tertiary or secondary carbon is attached with sodium metal.

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120 iupac name

Posted by Ankit Tomar 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Amandeep Jangu 8 years, 3 months ago

Unbinilium

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Kunal Arora 8 years, 3 months ago

Unbinilium

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What is gobal warrning

Posted by Sandeep Chandravanshi 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Shivam Dwivedi 8 years, 3 months ago

Some gases like CO2,sulphides,nitrogen oxides, CFC, traps the radiant heat from earth and creates greenhouse effect. It makes rise in earth's temperature, leading to many disaster like melting of glaciers, rise in sea level , uneven rain and water cycle and many more. This phenomenon is known as global warming.

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What is the valence bond theory

Posted by Sajjan Thood 8 years, 3 months ago

CBSE > Class 11 > Chemistry

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What is Rutherford drawbacks?

Posted by Sajjan Thood 8 years, 3 months ago

CBSE > Class 11 > Chemistry

2 answers

Shivam Dwivedi 8 years, 3 months ago

Inability to explain:- (1)stability of atom (2) distribution of electrons around nucleus (3) Line spectra

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Roshan Kumar 8 years, 3 months ago

He can't explain that the stability of an atom

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What is Bohr's atomic model

Posted by Adnan Alam 8 years, 3 months ago

CBSE > Class 11 > Chemistry

1 answers

Dipen Saka 8 years, 3 months ago

The Bohr model is a relatively primitive model of the <a href="https://en.wikipedia.org/wiki/Hydrogen_atom" title="Hydrogen atom">hydrogen atom</a>, compared to the <a href="https://en.wikipedia.org/wiki/Atomic_orbital" title="Atomic orbital">valence shell atom</a>. As a theory, it can be derived as a <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Orders_of_approximation#First-order" title="Orders of approximation">first-order approximation</a> of the hydrogen atom using the broader and much more accurate <a href="https://en.wikipedia.org/wiki/Quantum_mechanics" title="Quantum mechanics">quantum mechanics</a> and thus may be considered to be an <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Obsolete_scientific_theory" title="Obsolete scientific theory">obsolete scientific theory</a>. However, because of its simplicity, and its correct results for selected systems (see below for application), the Bohr model is still commonly taught to introduce students to <a href="https://en.wikipedia.org/wiki/Quantum_mechanics" title="Quantum mechanics">quantum mechanics</a> or <a href="https://en.wikipedia.org/wiki/Energy_level#Energy_level_diagrams" title="Energy level">energy level diagrams</a> before moving on to the more accurate, but more complex, valence shell atom. A related model was originally proposed by <a href="https://en.wikipedia.org/wiki/Arthur_Erich_Haas" title="Arthur Erich Haas">Arthur Erich Haas</a> in 1910, but was rejected. The quantum theory of the period between <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Planck#Black-body_radiation" title="Planck">Planck's discovery of the quantum</a> (1900) and the advent of a full-blown <a href="https://en.wikipedia.org/wiki/Quantum_mechanics" title="Quantum mechanics">quantum mechanics</a> (1925) is often referred to as the <a href="https://en.wikipedia.org/wiki/Old_quantum_theory" title="Old quantum theory">old quantum theory</a>

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Explain the principle of paper chromatography?

Posted by Jaya Geerthana 8 years, 3 months ago

CBSE > Class 11 > Chemistry