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According to Rydberg Balmer equation
{tex}\frac{1}{\lambda}{/tex} = {tex}R\left[\frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}}\right]=R\left[\frac{1}{1^{2}}-\frac{1}{n_{2}^{2}}\right]{/tex}
The wavelength {tex}(\lambda){/tex}will be longest when n₂is the smallest i.e. n = 2 and 3 for two longest wavelength lines.
For : n₂ = 2 , {tex}\frac{1}{\lambda}=\left(1.097 \times 10^{-2} \mathrm{nm}^{-1}\right)\left[\frac{1}{1^{2}}-\frac{1}{2^{2}}\right]{/tex}
{tex}\left(1.097 \times 10^{-2} \mathrm{nm}^{-1}\right) \times \frac{3}{4}=8.228 \times 10^{-3} \mathrm{nm}^{-1}{/tex} or {tex}\lambda=121.54 \mathrm{nm}{/tex}
For: n₂= 3; {tex}\frac{1}{\lambda}=\left(1.097 \times 10^{-2} \mathrm{nm}^{-1}\right){/tex}
= {tex}\left(1.097 \times 10^{-2} \mathrm{nm}^{-1}\right) \times(8 / 9)=9.75 \times 10^{-3} \mathrm{nm}^{-1}{/tex}; {tex}\lambda=102.56 \mathrm{nm}{/tex}

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Cal. The velocity of an electron in bohr's first orbit of Hydrogen atom

Posted by Yash Tiwari 6 years, 5 months ago

CBSE > Class 11 > Chemistry

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CBSE > Class 11 > Chemistry

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An organic acid contains C H and O. A 4.21 milligrams sample of acid is completely burnt it gives 6.21 mg of carbon dioxide and 2.54 mg of water what is the mass percentage of each element in the acid

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CBSE > Class 11 > Chemistry

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What is aufbau principal , hund rule , pauli rule

Posted by Ankit Gupta 6 years, 5 months ago

CBSE > Class 11 > Chemistry

1 answers

Udit Gaur 6 years, 5 months ago

Aufbau principle : the electrons are filled in the orbital according to their increasing order of energy Hund rule : no pairing of electrons can take place until and unless each of the orbital is singly occupied Pauli rule : no two electrons can have same set of four quantum numbers or two electrons in an orbital must different spins to attain stability in an atom where one electron revolves anti clockwise and the other clockwise or vice versa with charge +1/2 or -1/2 or vice versa accordingly

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Which of the following is the smallest cation? Na+ , Mg2+ , Ca2+ , Sc3+.

Posted by Amisha Aman 6 years, 5 months ago

CBSE > Class 11 > Chemistry

2 answers

Amisha Meena 6 years, 4 months ago

Na+ as Na is smallest also it is cation On comparing it with sc3+ .sc is much larger than na

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Udit Gaur 6 years, 5 months ago

Scandium 3+

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Why atoms with half filled and completely filled have extra stability?

Posted by Jiya Arora????? 6 years, 5 months ago

CBSE > Class 11 > Chemistry

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Udit Gaur 6 years, 5 months ago

Atoms are half filled and completely filled because of two reasons : 1. Symmetry distribution : we know that symmetry leads to stability. And an atom always tries to gain stability to remain balanced so half filled and complete orbitals are more stable 2. Energy exchange : the stabilising effect arises whenever two or more than two electrons have same spin are present in the degenerate orbitals of a subshell these electrons tends to exchange their places and hence releases more energy which is calledvas exchange energy More the exchange of places more is the exchange energy and as a result the orbital or atom will be more stable

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What is bond parameters?

Posted by Shivam Kumar Maurya 6 years, 5 months ago

CBSE > Class 11 > Chemistry

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Yogita Ingle 6 years, 5 months ago

Bond parameters refer to the characterization of covalent bond on the basis of various parameters like bond length, bond angle, bond enthalpy.

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Balance this equation NH3 + O2 = NO + H2O

Posted by Tehareen Navali 6 years, 5 months ago

CBSE > Class 11 > Chemistry

4 answers

Dheeraj Jandu 6 years, 5 months ago

No this is wrong ans.

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Jiya Arora????? 6 years, 5 months ago

4NH3 + 5O2 = 4NO + 6H2O

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Mahi ✌?? 6 years, 5 months ago

4NH3 + 5O2=4NO + 6H2O

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Palak Gambhir 6 years, 5 months ago

4NH3 + 5O2 = 4NO + 6H2O

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Posted by Ramprasad Solanki 6 years, 5 months ago

CBSE > Class 11 > Chemistry

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Abhinay Verma 6 years, 5 months ago

Atomic radius is calculated by measuring the distance between the two atoms of the same element if the combined by single covalent bond. Ionic radius is calculated by measuring the distance between the two positive and negative ions enough compound formed by exchange of charges

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Write short note on H-bonding in simple language.

Posted by Vaijyanti Dahiya 6 years, 5 months ago

CBSE > Class 11 > Chemistry

2 answers

Vaijyanti Dahiya 6 years, 4 months ago

Also explain its type.

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Jatin Garg???? 6 years, 5 months ago

H- bonding is the bonding of hydrogen with other atoms with a line from one side and a dotted line from other side. Types:- 1.Intermolecular H-bonding. 2.Intramolecular H-bonding.

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Atomic theory

Posted by Ram Kumar Sahu 6 years, 5 months ago

CBSE > Class 11 > Chemistry

1 answers

Kala Sandhya 6 years, 5 months ago

English

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Posted by Dipankar Kumar 6 years, 5 months ago

CBSE > Class 11 > Chemistry

1 answers

Ram Kumar Sahu 6 years, 5 months ago

Molarity is defined as the number of moles with solute /disolve per litre solution

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Posted by Sanjana Gupta 6 years, 5 months ago

CBSE > Class 11 > Chemistry

1 answers

Arti Singh 6 years, 5 months ago

You should study and work hard..

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Posted by Kala Babu 6 years, 5 months ago

CBSE > Class 11 > Chemistry

3 answers

Shreya Sharma 6 years, 5 months ago

And understand by theory and numerically

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Shreya Sharma 6 years, 5 months ago

Pay attention

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Kavya Singh Gaur 6 years, 5 months ago

By constant revision of topics

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Posted by Mansi Kaushik 6 years, 5 months ago

CBSE > Class 11 > Chemistry

2 answers

Jatin Garg???? 6 years, 5 months ago

Cathode rays consist of negatively charged particles. Anode rays consist of positively charged particles

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Jatin Garg???? 6 years, 5 months ago

Cathode rays travel in straight line.

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Posted by Aaradhya Asthana 6 years, 5 months ago

CBSE > Class 11 > Chemistry

1 answers

Vibes Positive 6 years, 5 months ago

The reaction is- C+2Cl2----CCl4 Given wt of C as 144g, so no. of moles of C will be=12moles Wt of Cl2 is 71g, no. of moles of Cl2=1 mole. So Cl2 is limiting reagent. Hence no of moles of CCl4 produced is 0.5 moles Mass of CCl4= 0.5*154=77g.

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CBSE > Class 11 > Chemistry

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CBSE > Class 11 > Chemistry

1 answers

Yogita Ingle 6 years, 5 months ago

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Posted by Ayush Vishwakarma?? 6 years, 5 months ago

CBSE > Class 11 > Chemistry

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Yogita Ingle 6 years, 5 months ago

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Mahi ✌?? 6 years, 5 months ago

Subatomic particles are particles much smaller than atom i.e. electrons, protons and neutrons.

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CBSE > Class 11 > Chemistry