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answer 6(c) and 7(d)

6(b)7(c) answer

c) is the correct answer

Yellow colourin NaCI is due to metal excess defect due to which unpaired electrons occupy anionic sites, known as F-centres.

These electrons absorb energy from the visible region for the excitation which makes crystalappear yellow

Energy of one photon is given by the expression E = hVwhere, h = PlancKs constant = 6.636 x 10^-34J s-1V= Frequency of radiation = 5x 10^14Hz= 5 x 10^14s-1.E= (6.636 x 10^34J s-1 x 5 x 10^14s-1)= 33.18 x 1020JOne mole of photon = 6.023 x 10^23photonsTherefore, Energy of one mole of photon = (6.023 x 10^23x 33.18 x 10^-20J) = 199.84 x 10^3JEnergy of one mole of photon = 199.84 kJ

Energy of one photon is given by the expression E = hVwhere, h = PlancKs constant = 6.636 x 10^-34J s-1V= Frequency of radiation = 5x 10^14Hz= 5 x 10^14s-1.E= (6.636 x 10^-34J s-1 x 5 x 10^14s-1)= 33.18 x 10^20JOne mole of photon = 6.023 x 10^23photonsTherefore, Energy of one mole of photon = (6.023 x 10^23x 33.18 x 10^-20J) = 199.84 x 10^3JEnergy of one mole of photon = 199.84 kJ

Each photon has energy ofhνh = planks constantν= frequency of lightIf there are N photons emitted then the total energy radiated isNhν.Average power is given byP=Energy/time=E/t=Nhν/tButN/t=nis the number of photons emitted per second.Therefore,n=P/hν.ν=c/λSo,n=Pλ/hcIf all the power is not radiated then the effective power = rated power x efficiency.So the number of photons emitted per secondn=Peffλ/c=P×ηλ/hcwhereη is the efficiency.In the problem power P = 150W, wavelengthλ = 4500A and efficiency is 8% = 0.08So number of photons emitted per second,n=(150×0.08*4500*10^-10)/(6.6×10&^−34)*(3*×10^8)= 27.2*10^1827.2*10^18number of photons will be emitted per second by the bulb

Ans :- Adecomposition reactionoccurs when one reactant breaks down into two or more products. It can berepresentedby the generalequation: AB → A + B. Inthis equation, ABrepresentsthe reactant that begins thereaction, and A and Brepresentthe products of thereaction.

b. Adelphoparasitism

Adelphoparasitism also known as sibling-parasitism, occurs where thehostspecies is closely related to theparasite, often in thesame familyorgenus.

NOTE THIS STEP :First we should calculate the number of moles of the gas under the given condition by the relationPV = nRT

HereP= 7.6 * 10-10mm Hg

= 7.6 *10-10/760 atm. = 1 * 10-12atm.

V= 1 litre

T= 273 + 0 = 273K

R= 0.082 litre atm./K/mol

Putting the values in equation

n=PV/RT= 1 *10-12*1/0.082 *273 moles

now since 1 mole = 6.023 * 1023molecules

10-12/0.082 *273 moles = 6.023 *1023*10-12/0.082 *273 molecules

= 2.7 * 1010molecules

If frequency of radiation =1.0x 10^¹⁵s⁻¹Energy of radiationis equal to Planck's Constant(6.626 x10^⁻³⁴m²kg / s) multiplied by frequencyEnergy of radiation=6.626 x 10^⁻¹⁹ J

An electron on the surface requires a certain amount of energy to free itself from the atom. That energy is (Threshold frequency x Planck's constant)Energy to free electron=4.638 x 10^⁻¹⁹ J

Kinetic Energy of electron= Energy of radiation-Energy to free electron

KE=1.988 x 10^⁻¹⁹ J≈ 2 x 10^⁻¹⁹ J

The frquency of the radiation emmited.

v = 900 kHz = 900 * 103Hz

= 900 * 103s-1

We know that wavelength * frequency = velocity (constant)

Or wavelength = velocity / frequency

where velocity = 3.0 * 108m s-1

wavelength = 3.0 * 108m s-1/ 900 * 103s-1

wavelength = 3 / 90 * 104m = 333m

Thus, wavelength of radiowave brodcast by the station is 333m...

The reaction can be feasible because , Ca2+ can combine with two anions and hence 1 Ca2+ can displace , 2Na+ and will form rings like structure by connecting with two -ve charged ions

so, it will replace 4Na+ ions

spontaneous changeoption(c)

option C might be correct option.

cosec(315°)= 1/sin(315)= 1/-sin(45) = -√2

cos(210)= cos(180+30°)= -cos(30)= -√3/2

If voltage and resistance are given and you have to find the value of current use Ohm's law V is equal to IxR

To give spiritual or intellectual insight (enlighten someone)

It is Mayer's equation.

Derivation:

ΔU = ΔQ + ΔW ΔU = Cv ΔT (At pressure is constant)

ΔQ = Cp ΔT (At pressure is constant)

ΔW = -P ΔV (Negative since the calculation been complete)

Pv = RT (1 mole of gas)

Because of pressure is constant, R is also constant

Change in V will make change in T

PΔV = R ΔT

Cv ΔT = CpΔT - RΔT

Divided by ΔT

Cv = Cp - R

Cp - Cv = R

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There are 2 C atoms, 6 H atoms and 1 O2atom in 1 molecule of ethanol.So,mass of 1 molecule = 2 X mass of C atom + 6 X mass of H atom + 1 X massof O2atom

= (2 X 12) + (6 X 1) + (1 X 16) {atomic wt. of C atom is 12,H atom is 1 and O2 atom is16}

= 24 + 6 +16 = 46.

Now, % composition ofcarbonatom is = (2 X mass of C atom)/mass of ethanol molecule= 2 X 12 / 46=24 / 46= 0.5217

To convert it into %;-

=0.5217 * 100%= 52.17 %

% composition ofhydrogen= (6 X mass of H atom)/mass of ethanol mol.= 6 X 1 / 46=0.1304=13.04%

% composition ofoxygen= (1 X mass of oxygen atom)/mass of ethanol mol.= 1 X 16 / 46= 16 / 46

To convert it into %;-

=0.3478 * 100%

=34.78%

thus, % composition of ethanol is52.17% C, 13.14% H and 34.78% Oby weight

1

orhto bromobenzene

1: bromobenzene 2: 1,3,5 tribromobenzene 3:benzybromide

PCRA stands for Petroleum Conservation Research Association(PCRA) is an organization established in India in 1978, under the aegis of the Indian Ministry of Petroleum and Natural Gas that is engaged in promoting energy efficiency in various sectors of the economy.

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Thermite is the chemical that is used in welding of railway tracks. It is normally a mixture of iron oxide and aluminium metal.

When reacted it, Aluminium reduces iron oxide to iron and itself gets oxidised i.e. a redox reaction occurs

Fe2O3+ 2 Al → 2 Fe + Al2O3

Due to the exothermic nature the reaction, iron is obtianed in molten form and can be used for welding of the railway tracks.

(i) X is Fe2O3, i.e. iron (III) oxide.

(ii)The reaction involved is thermite reaction or aluminothermy.

(III)

the volume of the air cool is 2657cm³

2657 is the right answer

According to Charles law, the volume is proportional to temperature at constant pressure. Now, if gas is heated up, it’s temperature rises hence, its volume also rises.in hot air balloon the air is heated, hence its volume increases so it’s density decreases. As we known that a fluid of less density floats on another object with less density, hence the hot air balloon gets heated up and rises up

you know,The operation of a hot air balloon depends on Charles' Law, the Ideal Gas Law, and Archimedes' Principle.

heliumballoondisplaces an amount ofair(just like the empty bottle displaces an amount of water). As long as the weight of the helium plus theballoonfabric is lighter than theairit displaces, theballoonwillfloat in the air. It turns out that helium is a lot lighter thanair.

Associated colloids are microheterogeneous systems in which the particles of the colloidal dispersed phase (micelles) are formed by the agglomeration of molecules or ions of the substance dissolved in the dispersion medium.

Associationcolloidsare microheterogeneous systems in which the particles of thecolloidaldispersed phase (micelles) are formed by the agglomeration of molecules or ions of the substance dissolved in the dispersion medium.

OR,

Associated colloids are the colloids which act as electrolyte at low concentration and show colloidal behaviour at high concentration.

Example: Soap solution.

Crystal Lattice

Crystal Lattice is a three-dimensional representation of atoms and molecules arranged in a specific order/pattern. In other words, a crystal lattice can be defined as a geometrical arrangement of constituent particles of matter (atoms, ions or molecules) as points in space. There are total 14 possible three-dimensional lattices. Crystal lattices are also known byBravais Lattices, named after the scientist Auguste Bravais.

Unit Cell

The smallest possible portion or part of the crystal lattice which repeats itself in different directions of the lattice is called the unit cell. Many unit cells combine to geometrically form the crystal lattice.

a. Radioactivity defined as the spontaneous emission of particles (alpha, beta,neutron) or radiation (gamma, K capture), or both at the same time, from the decay of certain nuclides that these particles are, due to an adjustment of their internal structure.Radioactivity can be natural or artificial. In natural radioactivity, the substance already has radioactivity in the natural state.In artificial radioactivity, the radioactivity has been induced by irradiation.

b.Thenucleusof this kind of atom issaidto be stable. In some atoms the binding energy is not strong enough to hold thenucleus together, and thenucleiof these atoms aresaidto beunstable.Unstableatoms will lose neutrons and protons as they attempt to become stable.

the

i.

The actual magnitude of a numerical value or measurement, irrespective of its relation to other values

The different 3-D shapes a molecule can turn itself into through rotation are calledconformational isomers.They’re the same molecule, but in different shapes.

Remember that opposite charges attract, like charges repel? Here’s two “conformations” of ethane, C2H6. In the “conformation” on the left, the bonds on the adjacent carbon atoms are closer together than they are in the “conformation” on the right.

Electrons don’t like each other’s company! (like charges repel). Since the bonds in the conformation on the right are farther apart, it is also more stable.

What this means is that the molecule on the left feels strain, which can be relieved through rotation of the C-C bond by 60 degrees. (a common term for this is “torsional strain”.)Like when you take a spring, and you twist it – there is a tension that arises there – it wants to twist back to its original state.

Aluminum sulfate + Barium chloride → Aluminum chloride + Barium sulfate.Al2(SO4)3+ 3BaCl2------> 2AlCl3+ 3BaSO4state two types in which this reaction can be classified.1) Precipitation Reaction2)Double displacement reaction

A propane molecule has three carbon atoms and eight hydrogen bonds. Propane has a molecular mass of molar mass is 44.097 g/mol and has a free rotation and a tetrahedral conformation. The structure of propane is given as-