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Electron gain enthalpy is defined as the amount of energy released when an electron is added to an isolated gaseous atom. During the addition of an electron, energy can either be released or absorbed. Sign Convention For Electron Gain Enthalpy: Negative: When energy is released while accepting an electron.

when a electron is recieved by an gaseous atom energy can either be released or absorbed

Electron gain enthalpy is sometimes also referred to asElectron affinityalthough there is a minute difference between them. Electron gain enthalpy is defined as the amount of energy released when an electron is added to an isolated gaseous atom. During the addition of an electron, energy can either be released or absorbed .

This is due to their small size and higher effective nuclear charge. Due to these two parameters halogens easily gain one electron to complete their octet and attain Noble gas configuration.

Even though Fluorine has the highest electronegativity among all the elements and it should have the highest electron gain enthalpy among all the halogens butthis is an exception and chlorine has higher electron gain enthalpy than Fluorine.

The reason for this is that the size of Fluorine atom is very small and hence there is very high inter-electronic repulsion among the electrons of fluorine.This makes incoming of another electron not very favourable.Even though fluorine has large negative electron gain enthalpy but for chlorine its even more negative.

(b) : As we move from left to right across a period, ionisation enthalpy increases with increasing atomic number. So the order of increasing ionisation enthalpy should be B < C < N < O. But N(1s2 2s2 2p3 ) has a stable half filled electronic configuration. So, ionization enthalpy of nitrogen is greater than oxygen. So, the correct order of increasing the first ionization enthalpy is B < C < O < N.

answer is option (2)B<C<N<O

2) is the answer for you

Above answers are absolutely correct..

Elements in increasing order of metallic character :-AL<Mg<Na<K

The increasing order of their metallic character = Mg<Na<K

Alternative energy is any energy source that is an alternative to fossil fuel. These alternatives are intended to address concerns about fossil fuels, such as its high carbon dioxide emissions, an important factor in global warming.

Commonly known alternative energy sources

HydroelectricEnergy.

Solar Energy.

WindEnergy.

Biomass Energy.

Geothermal Energy.

TidalPower.

In -OR group R is alkyl group that means O is connected with carbon.hence the releasing effect of r group is more.So -I :-OR>-OH.

thanks

option 1

Mg -Mg2++ 2electronas after losing two electrons it will attain +2 oxidation state

and for Cl+e- --Cl^-1after gaining an electron chlorine will get a negative charge and it's.octet will be completed.

good job.thank you

We have Zn(s) + Cu2+(aq)------- Zn2+(aq) + Cu(s)gibbs free enrgy =-n FEwhere n is the number of electron=2F is the faradays constant,here it is 96500CE is the EMF of the cell =1.1VGibbs free energy=-2*96500*1.1 J= -212.3 KJ

the electrode potential of standard hydrogen electrode is taken as 0option A is correct answer..

0 as Hydrogen act as reference electrode

An electrode is a small piece of metal or other substance that is used to take an electric current to or from a source of power, a piece of equipment, or a living body.

Electrode potential, E, in chemistry or electrochemistry, according to a IUPAC definition, is the electromotive force of a cell built of two electrodes: on the left-hand side of the cell diagram is the standard hydrogen electrode, and on the right-hand side is the electrode in question.

An electrode is a small piece of metal or other substance that is used to take an electric current to or from a source of power, a piece of equipment, or a living body.

Electrode potential, E, in chemistry or electrochemistry, according to a IUPAC definition, is the electromotive force of a cell built of two electrodes: on the left-hand side of the cell diagram is the standard hydrogen electrode, and on the right-hand side is the electrode in question.

1

2

3

According to a formula Moles = volume/22.4

Given, Volume = 5.6

On solving (i) and (ii) we get

= 5.6/22.4

= 0.25 moles

= 0.25 * 6.023 * 10^23

= 1.50

i)Delta G=0: the system is at equilibrium and there is no netchangeeither in forward or reverse direction.ii)WhenDelta G>0 is , the process isendergonicand not spontaneous in the forward direction. it will proceed spontaneously in the reverse direction to make more starting materials.

Ag has atomic mass of 108 which is equal to its 1 mole.

Acc to avagadro number 1 mole has 6.O23×10^23 atoms . Which means 108 g of Ag contains 6.023×10^23 atoms.

Therefore 5 g of silver will have : O.28 × 10^23 atoms.

ok thanks

c is the correct answer......

C is the correct answer

Molar mass of H2SO4 = 98g/mol = MmD =density = 1.84g/ccW/w = 98%V = 1dm3 = 1L = 1000ml = 1000ccMass of solution = V x DM = 1000 x 1.84 = 1840g per 1000ccUsing w/w, 98% of 1840g = H2SO4= (98/100) x 1840 = 1803.2g = mNos of moles = m/Mm = 1803.2/98 = 18.4moles per 1000ccThus, molarity = 18.4M (18.4mol/dm3

when n = 3 , L can be only 0,1,2

so, no electons will be there in L = 3

option D

plz explain it more clearly

this is again the definition...

for N = 3 , L can be up to number < 3 => 0,1,2

so, there can't be L = 3 for n = 3 , => 0 electons

also, L = 3 means f orbitals and have your heard about 3f orbital ?? because there is not any..

When a solid is heated,vacancydefect can arise. A solid crystal is said to havevacancydefect when some of the lattice sites are vacant.Vacancy defect leads to a decrease in the density of the solid.

Like my answer if you find it useful;

thank you..

K.Emax = eV°

option A

Thesiemens(symbolized S) is theSI unit of electrical conductance

Metronidazole is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It is effective for dracunculiasis, giardiasis, trichomoniasis, and amebiasis.

Thereduction potential of an electrodecan beincreasedeither byincreasingthe concentration of metal cation [Mn+(aq)] or temperature T..

Full answer after T.. What is there??

The five isomers ofhexaneare:hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane. They are constitutional isomers because they each contain exactly the same number and type of atoms, in this case, six carbons and 14 hydrogens and no other atoms.

उनके जाली बिंदु से आयनों के लापता होने के कारण शोट्की दोष उत्पन्न होता है और जब लापता आयन अंतरालीय स्थलों पर कब्जा कर लेते हैं तो फ्रेनकेल दोष उत्पन्न होता है। ... AgBr में, Ag + आयन आकार में छोटा है और जाली बिंदु से हटाए जाने पर वे अंतरालीय स्थलों पर कब्जा कर सकते हैं और इसलिए फ्रेनकेल और शोट्स्की दोनों दोष दिखाते

This arrangement is what we mean by a heat exchanger: the gas jets cool down and thewaterheats up. A heat exchanger is a device that allows heat from a fluid (a liquid or a gas) to pass to a second fluid (another liquid or gas) without the two fluids having to mix together or come into direct contact

Heatcan be transferred from one place to another by three methods: conduction in solids, convection of fluids (liquids or gases), and radiation through anything that will allow radiation to pass. The method used to transferheatis usually the one that is the most efficient.

Conduction, convection, and radiation:three types of heat transfer

Conduction is the transfer of heat between substances that are in direct contact with each other. The better the conductor, the more rapidly heat will be transferred. Metal is a good conduction of heat. Conduction occurs when a substance is heated, particles will gain more energy, and vibrate more. These molecules then bump into nearby particles and transfer some of their energy to them. This then continues and passes the energy from the hot end down to the colder end of the substance.

CONVECTION--

Thermal energy is transferred from hot places to cold places by convection. Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas. Cooler liquid or gas then takes the place of the warmer areas which have risen higher. This results in a continous circulation pattern. Water boiling in a pan is a good example of these convection currents. Another good example of convection is in the atmosphere. The earth's surface is warmed by the sun, the warm air rises and cool air moves in.

RADIATION--

Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object as is the case with conduction and convection. Heat can be transmitted through empty space by thermal radiation often calledinfrared radiation. This is a typeelectromagnetic radiation. No mass is exchanged and no medium is required in the process of radiation. Examples of radiation is the heat from the sun, or heat released from the filament of a light bulb.

Two postulates of Dalton atomic theory are:1) Atom is the smallest unit of matter that can take part in a chemical reaction2)Atoms of the same element can combine in more than one ratio to form two or more compounds.

Hydrogen sulphide reacts with brass. Hence option B is correct.

A) Hydrogen sulphide is the correct answer .

A) hydrogen sulphide is the correct answer

Ans: A) Constant Proportion

Law of constant proportion states that the composition of a chemical compound is independent of its source and method of preparation and the percentage of the constituent elements remain constant

Constant proportion is the right answer

Ethane hasseven covalent bonds.6C-H bonds and 1 C-C bond

option d is correct

co-ordinate bond is in between Cu-(NH3)

and electorvalent bond is in between so4- and [Cu(NH3)]

and covalent bond is in NH3.

Thanks

Covalent bonds, which hold the atoms within an individualmoleculetogether, are formed by the sharing ofelectronsin the outeratomic orbitals.

Vulcanizationis a chemical process for converting naturalrubberorrelatedpolymers into more durable materials via the addition of sulfur or other equivalent curatives or accelerators. These additives modify the polymer by forming cross-links between individual polymer chains.