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What would be the nature of solid if there is no energy gap between valence band and conduction band?

Posted by Saurav Sharma 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Sayeda Iram Ateeq 6 years, 7 months ago

The nature of the solid will be conductor.

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Why Raoult's law considerd as a special case of Henry's law?

Posted by Rahul Nehwal 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Gaurav Seth 6 years, 7 months ago

Raoult’s law as special case of Henry’s law

At a given temperature liquids vaporize. At equilibrium the pressure exertedby the vapour of the liquid over the liquidphase is referred to as vapour pressure.
According to Raoult’s law, vapour pressure of a volatile component in a given solution ca be defined by p_i = p_i ⁰ x_i
In an answer of a gas in a fluid one of the segments is volatile to the point that it exists as a gas and solvency is given by Henry's law which expresses that p = K_H x
Comparing both the equations we get that partial pressure of the volatile component or gas is directly proportional to its mole fraction in solution. Proportionality constant K_H differs from p₁⁰
Therefore, Raoult's law turns into a unique instance of Henry’s law in which K_H get to be equivalent to p₁⁰.

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Phenol associates in benzene to a certain extent to form a dimer. A solution containing 20g of phenol in 1kg of benzene has its f.p lowered by o.69k calculate the fraction of phenol that has Dimerised

Posted by Vivek Mishra 6 years, 7 months ago

CBSE > Class 12 > Chemistry

3 answers

Himanshu Shekhar 6 years, 7 months ago

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Gaurav Seth 6 years, 7 months ago

We know,

K_f = Molal depression constant ( 5.12 K Kg/mol)

w_B = weight of the solute

w_A = weight of the solvent

M_B = Observed molar mass of the solute.

Substituting the values we get,

Calculated molecular weight of phenol = 12 x 6 + 1 x 5 + 16 + 1

= 94 g

The association of phenol can be represented as:

Here, x is the degree of association.

The total number of particles after association

Now,

Hence, the fraction of phenol dimerized = 73%

0Thank You

Gaurav Seth 6 years, 7 months ago

Question:

Phenol associates in benzene to certain extent to form a dimer. A solution that is containing 20 x 10-3kg of phenol dissolved in 1 kg of benzene has its freezing point decreased by 0.61 K. Calculate the fraction of phenol that has dimerised.

Solution:

∆ Tf = Kf wB 1000/ wA MB

0.69 = 5.12 x 20 x 10^-3 x 10^3 / 1 x MB

MB = 5.12 x 20 / 1 x 0.69

Molecular weight of phenol = 94g

Calculated M . W / observed M . W = No. of particles after association/ No. of particles before association

94 / 148.4 = 1 - x/2 / 1

x = 0.73 per mole

Fraction of C6H5OH = 0.73 x 100 = 73%

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Name the material used for making semipermeable membrane

Posted by Rajni Sharma 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Gaurav Seth 6 years, 7 months ago

Cellulose acetate, potassium ferrocyanide, etc. are used as semipermeable membrane for carrying out reverse osmosis.

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Why scandium is a transition metal??

Posted by Priyanshi Jaiswal 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Antriksh Bohara 6 years, 7 months ago

scandium is a transition metal because it is found between s and p block elements , and in crystal field five degenerate d orbitals loose thier degenracy and split into two sets t2g and eg

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About molarity

Posted by Prince Tiwari 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Mehak Sharma 6 years, 7 months ago

Moles of solute per volume of soln

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Swadhyay ch no .2

Posted by Arun Vachheta 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

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During making lemonade when we mix sugar partially and add lemon juice how does the solubility of sugar affected

Posted by Mehak Sharma 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Which is the good book for Organic Chemistry?

Posted by Isha Vishwakarma 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Himanshu Shekhar 6 years, 7 months ago

Solomon

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Acidic strength in increasing order of the following compound - Phenol ,p-nitrophenol, o,p-nitophenol

Posted by Zoya Ali 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Pragati Gola 6 years, 7 months ago

Thsese are already in increasing order

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Solubility of Nitrogen gas at 25℃ at 1atm is 0.00068mol/lit.What is the concentration of Nitrogen dissolvdd in water under atmospheric condition?

Posted by Mamata Lenka 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Gaurav Seth 6 years, 7 months ago

Since in this problem ‘k’ is not given so we have to find out.

Applying Henry’s equation,S = k P

k= S/P = 6.8 X 10^-4 mol L^-1 = 6.8 X 10^-4 mol L^-1

So the solubility of N₂ at 0.78 atm:

S= (6.8 X 10^-4 mol L^-1) (0.78 atm) = 5.3 x10^-4 M

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Hume ek subject ko ketna rime daena cha hea a

Posted by Gursharn Kaur 6 years, 7 months ago

CBSE > Class 12 > Chemistry

2 answers

▪▪Amrit▪▪ ❤ 6 years, 7 months ago

2 hours maximum 30 min minimum

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Ravikant Sharma Pandit 6 years, 7 months ago

1:30min

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Explain swarth reaction

Posted by Priya Yadav 6 years, 7 months ago

CBSE > Class 12 > Chemistry

2 answers

Nishu Sahu 6 years, 7 months ago

It is a process of formation of fluroalkane. In this chloro or bromo alkane react with metalfloride to give fluroalkane. e.g.- CH3Cl + AgF----------->CH3F + AgCl

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Vineet Garg 6 years, 7 months ago

Swartz reaction CH3Br +AgF --> CH3F + AgBr

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2.82gram of glucose (molar mass 180) dissolve in 30gram of water 1.calculate the molality 2.mole fraction of glucose and water

Posted by Achou Leimapok 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Gursharn Kaur 6 years, 7 months ago

Given weight= 2.82 g Molar mass= 180 No. Of moles= given weight/ molar mass = 0.0157 Molality= no of moles / mass × 1000 = 0.52 mol / kg No.of moles of water = 1.67 Mole fraction if glucose = 0.0157/0.0157+1.67 Mole fraction of water= 1.67/1.67+0.0157 or 1- mole fraction of glucose

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What is stedio isomerism

Posted by Vineeta Singh 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Understanding of all types of particle

Posted by Korningstar Nongsiej 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

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My sister got 98.4 marks in 10th I think checking was very leniant...

Posted by Paras Kundu 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Navaneetha Krishnan Bnk 6 years, 7 months ago

Congratulation

1Thank You

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What's the difference between ortho and para...?

Posted by Rahul Kumar 6 years, 7 months ago

CBSE > Class 12 > Chemistry

3 answers

Gursharn Kaur 6 years, 7 months ago

Difference is omly about the spins and the position of subsituent attached to aromatic compound

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Yogita Ingle 6 years, 7 months ago

Ortho- describes a molecule with substituents at the 1 and 2 positions on an aromatic compound. In other words, the substituent is adjacent or next to the primary carbon on the ring.

The symbol for ortho- is o- or 1,2-<name of compound>

Para-

Para- describes a molecule with substituents at the 1 and 4 positions on an aromatic compound. In other words, the substituent is directly opposite the primary carbon of the ring.

The symbol for para- is p- or 1,4-<name of compound>

2Thank You

Abhi Saini 6 years, 7 months ago

I. Bengnene ring 1,2 position is ortho and 1,3 positiom is meta

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How we change molality value of a solution into molrity value.?

Posted by Himanshu Raj 6 years, 7 months ago

CBSE > Class 12 > Chemistry

2 answers

Gursharn Kaur 6 years, 7 months ago

Simply multiple volume by density to get the value of mass put put the value of this mass in place of the volume

1Thank You

Sinchana Malagond 6 years, 7 months ago

Molality is equal to 1000 into molarity / density into 1000 minus molecular mass into molarity

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can you think why does no2 group show its effect only at ortho and para positions and not at the meta position

Posted by Samuel Stephen 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Shubham Prajapati 6 years, 7 months ago

I think due to +m effect ..+m/-m effect doesn't show on meta.. Only or ortho and para position

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An element X (atomic weight = 24 gm/mol) forms a face centered cubic lattice. If the edge length of the lattice is 4×10^-8 cm and the observed density is 2.40×10^3 kg/m^3 , then the percentage occupancy of lattice points by element X is : (Use NA=6×10^23): Options are: (A) 96 (B) 98 (C) 99.9 (D) None of these

Posted by Pranjal Pritam 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

ANSWER

Why is it necessary to use a salt bridge in a galvanic cell?

Posted by Yash Garg Garg 6 years, 7 months ago

CBSE > Class 12 > Chemistry

5 answers

Mehak Sharma 6 years, 7 months ago

To equalize the ions

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Abhi Saini 6 years, 7 months ago

Yes bacause it maintain cotinuty

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Harsh Kaushik 6 years, 7 months ago

to equalise the concentration of both xinc and copper

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Shubham Kumar 6 years, 7 months ago

Nbb

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Yogita Ingle 6 years, 7 months ago

In the electrochemical cell a salt bridge performs the following functions:

a) It allows the flow of current by completing the circuit.
b) It maintains electrical neutrality.

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Write a short note on finkelstein reaction

Posted by Sanjeet Barnwal 6 years, 7 months ago

CBSE > Class 12 > Chemistry

2 answers

Aisha Patel 6 years, 7 months ago

Finkelstein reaction is done in which sodium iodide react with alkyl halide in presence of dry acetone which gives alkyl iodide..

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Yogita Ingle 6 years, 7 months ago

Treatment of a primary alkyl halide or pseudohalide with an alkali metal halide (e.g. KF, KI) leads to replacement of the halogen via an SN2 Reaction. this us called Finkelstein Reaction.

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What is plane polarization

Posted by Ayushi Yadav 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

S.....Sharma☺??? .. 6 years, 7 months ago

A plane polarized light is that in which wavelenghth of every colour is same

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What is gibbs energy?

Posted by Abhishek Kala 6 years, 7 months ago

CBSE > Class 12 > Chemistry

4 answers

Mehak Sharma 6 years, 7 months ago

Free energy G=-nfe

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Abhi Saini 6 years, 7 months ago

_ g

0Thank You

Hemant Bhardwaj 6 years, 7 months ago

Free Energy present in system that can be converted into work done

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Yogita Ingle 6 years, 7 months ago

Gibbs free energy is the energy needed to create a system out of nothing in an environment at both constant pressure and constant temperature.

It is defined mathematically by the equation.

G = H - TS

Where H = heat content, S = entropy of the system, T = absolute temperature

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Why molecular weight increases kr decreases on the basis of colligative properties

Posted by Ashima Abrol 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

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What is electrophilic?

Posted by Babitarijal Babitarijal 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

S.....Sharma☺??? .. 6 years, 7 months ago

The electron loving species or we can say that the proton rich species and it having positive charge and for contain stable it want electron

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How to use log table for electrochemistry

Posted by Gaurav Jha 6 years, 7 months ago

CBSE > Class 12 > Chemistry

2 answers

Sourabh Singh 6 years, 7 months ago

If the no is not in the form 0.000 then Say 468.2 Then it can be written as 4.682*10^-2 And so we can find it separately and then multiply it with each other

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Sourabh Singh 6 years, 7 months ago

For finding the value of log first of all we should take a number in the form 0.000 Lets take a number 3.456 Then see the log table present at the last page of chemistry part I Now in N find first two numbers,in this case find 34 Then see the no. In the columb headed by 5 .the no.is 5378 Now the last digit is left i.e 6 Then we will see the columb headed by no. 6 in mean difference present at right side of the log table. The no is 8. Now two find its value we have to add 5378+8=5386. So now by these steps we can find log easily

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In a dry cell the buildup of ammonia around the carbon cathode should disrupt the electric current, but in practice this does not happen

Posted by Juhi Sharma 6 years, 7 months ago

CBSE > Class 12 > Chemistry

0 answers

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What is dizonium salt?

Posted by Neha Joshi 6 years, 7 months ago

CBSE > Class 12 > Chemistry

1 answers

Yogita Ingle 6 years, 7 months ago

The diazonium salts (di refers to ‘two’, azo is indicative of ‘nitrogen’ and ium implies that it is cationic in nature), or diazonium compounds, are the class of organic compounds with general formula R−N₂⁺X⁻ where X is an organic or inorganic anion (for example, Cl^–, Br^–, BF₄^–, etc.) and R is an alkyl or aryl group. Hence, they have two nitrogen atoms with one being charged. Benzenediazonium chloride (C₆H₅N₂⁺Cl^–), benzenediazonium hydrogensulphate (C₆H₅N₂⁺HSO₄^–), etc. are some of the examples of the diazonium salt.