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Rate Law : It is the expression which relates the rate of reaction withconcentrationof the reactants. The constant of proportionality ‘k’ is known as rate constant.

Rate constant: When the concentration of reactants isunity, then the rate of reaction is known as rate constant. It is also called specific reaction rate.

ans me

Hyperconjugation is the stabilising interaction that results from the interaction of the electrons in a sigma bond (usually C-H or C-C) with an adjacent empty or partially filled p-orbital or a pi orbital to give an extended molecular orbital that increases the stability of the system.

Anorbitalis a wave function for an electron defined by the three quantum numbers, n, ℓ and ml.Orbitalsdefine regions in space where you are likely to find electrons.p orbitals(ℓ = 1) are dumb-bellshaped. The three possiblep orbitalsare always perpendicular to each other.

p-orbitals are in (dumb bell) shapehope this will help you like my answer and MARK IT AS BEST ANSWER

p-orbitals are dumb bell shapedI hope it will be the most suitable answer

p orbital is in dumbbell shape

p orbital is dumbbel shape

p orbital is in dumbell shape due to an electron in p orbital can have equal probability of being either half only the two electrons present so it is in dumbell shape

dumbbell shape is the right answer for this question

I think dumbell shape

the right answer is dumb bell shape of p orbitals

P-ORBITAL IS DUMB BELL

Withsp3d2, the s, p and d orbitals which arehybridizedall come from the same energy level, for instance, it has been taught that when sulfur combines with six fluorine atoms to make SF6 that the 3s, 3p and two 3d orbitals hybridize to make thesp3d2 hybridorbital set. But d2sp3 is different.

17.Hyperconjugation is the stabilising interaction that results from the interaction of the electrons in a σ-bond (usually C-H or C-C) with an adjacent empty or partially filled p-orbital or a π-orbital to give an extended molecular orbital that increases the stability of the system.

18.Preparation of Lassaigne’s Extract:A small pellet of metallic sodium together with a little of the substance is heated to red hot in an ignition tube. It is then suddenly plunged into about 10ml of distilled water in a china dish. The mixture is boiled well and filtered. The filtrate is the Lassaigne's extract.

13. Benzeneand its homologues may bepreparedby the following methods.

By the decarboxylation of sodium benzoate.

By heating phenol with zinc.

By the polymerization of ethyne (acetylene)

By the reduction ofbenzenediazonium chloride.

By the hydrolysis of sulphonic acid.

14. Haloarenes are chemically less reactive than haloalkanes. They can undergo the following reactions:

Replacement by hydroxy group (formation of phenol)

When aryl halides are heated at 623 K and under pressure (300 atm), with aqueous solution of sodium hydroxide, the halogen atom is replaced by hydroxyl group forming phenol. Firstly sodium phenoxide is formed, which on acidification gives phenol.



This reaction forms the basis for the manufacture of phenol by Dow's process.

Substitution by amino group (formation of aniline)

The halogen atom is replaced by amino group when aryl halides are heated with aqueous ammonia in the presence of cuprous oxide (catalyst) at 475 K and under a pressure of 60 atm.,



Substitution by cyano group (formation of cyanobenzene)

The halogen atom is replaced by cyano group on heating with anhydrous cuprous cyanide in the presence of pyridine or dimethylformamide (DMF).



The cyanobenzene can be converted into other useful compounds like Benzamide, benzoic aid and benzylamine under different conditions.

Effect of substituents in haloarenes (aryl halides) on the reactivity

The reactivity of haloarenes is markedly affected by the presence of certain groups at certain positions of the ring. The presence of electron withdrawing groups such as -NO2,-CN, -COOH, etc. at 'o' and 'p' positions to the halogen atom, greatly activates the halogen towards nucleophilic substitution reactions. For example, chlorobenzene is converted into phenol by aqueous NaOH only at temperatures above 573 K, whereas 'p' chloronitrobenzene is converted into nitrophenol by aqueous NaOH at a lower temperature of 433K. As the number of ortho and para nitro groups on the ring is increased the reactivity increases.

When salt is spread over snow covered roads, snow starts melting from the surface because of the depression in freezing point of water and it helps in clearing the roads.

Mass of chlorophyll = 5.0 gPercentage of Mg = 2.68 g2.68 x 2 0Mass of Mg in 5.0 g of chlorophyll = 2.69 x 5.0/100= 0.1345 g6.022 X {{10}^{23}} atoms of magnesium = 24 g.’. 24 g of Mg contains 6.022 X {{10}^{23}} atoms

0.1345 g of Mg contains 6.022 X ${{10}^{23}}$/24x 0.1345

= 3.73x {{10}^{21}} atoms

Initial concentration of A = [Ao]Amount of A left inn1half lives =(12)n1[Ao]

Initial concentration of B = [Bo]Amount of A left inn2half lives =(12)n2[Bo]

According to the question, concentration of both will be same,

[Ao]/2^n1=[Bo]/2n^24/2^n1=1/2^n2(SinceAo=4Bo)2^n1/2^n2=2^22(n1−n2)=2^2n1−n2=2n2=n1−2Also,t=n1×t(1/2A)t=n2×t(1/2B)Let the concentration of both become equal after time t

n1×t1/2/n2×t1/2=n1×5/n2×15=1n1/n2=3n1=3n2Usingaboverelationinequationn2=n1−2n2=3n2−2n2=1Therefore,n1=3Puttingthisvaluein,t=n1×t1/(A)=3×5=15minutes

Absolute zero,temperatureat which athermodynamicsystem has the lowest energy. It corresponds to −273.15 °C on theCelsius temperature scaleand to −459.67 °F on theFahrenheit temperature scale

see if there is no volume then where is the space for gas to move

i meant that without volume (space) there cannot be any thing soAt absolute zero volume of a given mass of a gas becomes absolutely zero

Order of reaction = 1Let the initial concentration be [A]0 = 100%[A]t = 100 -75 = 25%Rate law for first order rectionK = (2.303/t)log[A]0/[A]tfor (75%) - time is 30 minutes

Substituting the values we get K = (2.303/30)*log[100/25]And k = 0.04621 per minute

now % completion is 99.9 [A]t = 0.1%

therefore t = (2.302/k)*log[100/0.1] t = (2.303/0.04621)*(3) = 149.5 = 150mins.

2 non-reactive gases A & B present in a container with partial pressure 200 and 180 mm of Hg. When a third non-reactive gas C is added, then the total pressure becomes 1 ATM. What is the mole fraction of C?

Answer

4

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5 ANSWERS



Ameya Deshmukh, studies Science and Mathematics at St. Joseph's Convent High School, Jalgaon (2019)

Answered Sep 16, 2017

According to Dalton's Law of Partial Pressures, here, the pressure exerted by C will not be affected by A and B.

And the total pressure exerted will just be the scalar sum of all the partial pressures.

Letxbe the partial pressure of C.

Hence-

200 mm of Hg + 180 mm of Hg + x =1 atm

x = 1 atm-380 mm of Hg

But 1atm = 760 mm of Hg.

Therefore,x = 760-380=380 mm of Hg.

Moreover,

Partial Pressure Mole fraction × Total Pressure

Hence-

380 mm of Hg= X of A × 760 mm of Hg.

X of C = 1/2 =0.5

The mole fraction of C is0.5

PARTIAL PRESSURE OF HYDROGEN= MOLE FRACTN OF H2X TOTAL PRESSURE

moles of H2= 2/2= 1

MOLES OF SO2= 32/64 = 0.5

P.P OF H2= 1/ 1.5 X TOTAL PRESSURE = 2/3 0F TOTAL PRESSURE(3RD OPTN)

PARTIAL PRESSURE OF HYDROGEN= MOLE FRACTN OF H2X TOTAL PRESSURE

moles of H2= 2/2= 1

MOLES OF SO2= 32/64 = 0.5

P.P OF H2= 1/ 1.5 X TOTAL PRESSURE = 2/3 0F TOTAL PRESSURE(3RD OPTN)

thanks

First order reaction .As the unit is min^-1

half life =0.693/0.346=2min

(i) First order. (ii) S^-1/time^-1

A dipole moment is the product of the magnitude of the charge and the distance between the centers of positive and negative charges. It is denoted by the Greek letter ‘µ’.

Artificial diamonds are made by subjecting pure carbon or graphite to high pressure and temperature this method of preparing diamonds is called High pressure,High temperature (HPHT).Second method of preparing diamonds is (CVD) Chemical vapour deposition in this method hydrogen and carbon gas are kept in chamber which contain filament and microwave and again same process is repeated in which high temperature and pressure is applied. Natural diamonds have internal flaws but artificial diamond do not have any flaws

Since Caq/Corg½ is practically constant benzoic acid exists as a dimer (n=2) in benzene.Molecular condition of benzoic acid in benzene is 1/slope = n = 2 , molecules of benzoic acid associate in benzene.

The powder coatingthat gets applied is just that-a powder. It basically gets sprayed onto the surface and then dries to form a coating. The surface of the item that is being coated with Teflon is sandblasted so that it receives a lot of tiny micro-abrasions. This rougher surface is easier for the non-stick Teflon to grab onto. However, this method has been shown to create a rather weak bond with the item it is being coated onto. This is why some cookware may be more easily scratched than others.

thankyou mam but I have to complete it in my activity book because of that I want answer in points such as title , introduction , framework , procedure , conclusion and persnol opinion . mam if u can give ans in points please

Oxygen is the gas that supports burning.

a) Spontaneous Combustionb) Rapid Combustionc) Explosive Combustion(or explosion)d) Spontaneous Combustion

Reaction precedes as :

NaOH + HCl ----- NaCl + H2O

This is a neutralization reaction where one mole oh HCl reacts with one mole of NaOH to form the salt. One mole of NaCl is formed.Hence, entire NaOH and HCl is utilized to form the salt. The resulting solution is neutral.

let V be the volume needed to make 0.2M

now no. of moles in the initial solution = 0.5*(0.016)

so, final concentration is 0.2 => 0.2 = 0.5*(0.016)/V => V = 0.5*(0.016)/0.2 = 0.04 l = 40ml.

so, we will add 40-16 = 24 ml more water to the solution to convert 0.5M to 0.2M

magnesium is not more reactive as calcium hence calcium can react with react with cold water but magnesium cannot is can react with hot water .So when it reacts with hot water it forms magnesium hydroxide and hydrogen .The hydrogen gas evolved doesn't catch fire because the heat evolved is very low . But it forms bubbles and stick to the surface of magnesium and thus as a result magnesium starts floating on water due to the hydrogen gas.hence magnesium ribbon start floating on water.

This minimum temperature is called ignition temperature.

Such substances are called inflammable substances.

Let the number of electrons in ion = xNumber of neutrons = x+0.304x = 1.304xNumber of electrons in neutral atom = x+3Number of protons in neutral atom = x+3Mass number = 56(x+3)+(1.304x)=56X = 23Number of protons = x+3 = 26Symbol of ions = Fe3+

HCl = 1+35.5= 36.5g/molHNO3 = 1 +14 +3(16) = 1 + 14 + 48 = 63 g/molC2H2 = 2(12)+2(1) = 24 + 2 = 26 g/mol

The elements which give the greatest number of oxidation states occur in or near the middle of the series. For example, manganese exhibits all the oxidation states from +2 to+7.

in the first element pakistan ki maa ka bhosda transition with series

1)Electronic configuration of Mn2+is [Ar]183d5.

Electronic configuration of Fe2+is [Ar]183d6.

It is known that half-filled and fully-filled orbitals are more stable. Therefore, Mn in (+2) state has a stable d5configuration. This is the reason Mn2+shows resistance to oxidation to Mn3+. Also, Fe2+has 3d6configuration and by losing one electron, its configuration changes to a more stable 3d5configuration. Therefore, Fe2+easily gets oxidized to Fe+3oxidation state.

2)The more extensive themetallic bonding of an element, the more will be its enthalpy of atomization. In all transition metals (except Zn, electronic configuration: 3d10 4s2), there are someunpairedelectrons that account for their strongermetallicbonding

copper has highest second ionisation enthalpy

Manganese, which is in the middle of the period, has thehighest numberofoxidation states,

i) Cu2+ has an unpaired electron (its configuration is [Ar] 3d9), whereas Zn2+ has all paired electrons (configuration [Ar] 3d10). Pairing electrons leads to diamagnetism, and unpaired electrons leads to paramagnetism. Also, the unpaired electron in the copper ion allows electron transition in the visible region to take place, so the ion is coloured.

ii) Transition metals are large in size and contain lots of interstitial sites. Transition elements can trap atoms of other elements (that have small atomic size), such as H, C, N, in the interstitial sites of their crystal lattices. The resulting compounds are called interstitial compounds.

i

iii)

Boyle law : The law, discovered by Robert A. Boyle in 1662, states that at a fixed temperature, the volume of gas is inversely proportional to the pressure exerted by the gas. In other words, when a gas is pumped into an enclosed space, it will shrink to fit into that space, but the pressure that gas puts on the container will increase.

Charles states : It states that if pressure remains constant, the volume of a mass of gas is proportional to its absolute temperature. The absolute temperature is always 273 Kelvin more than the centigrade temperature.

thanks😀😁😂

Liquidstake on the shape of their container.

Theliquid stateof matter is an intermediatephasebetween solid and gas.

Like the particles of a solid, particles in aliquidare subject to intermolecular attraction; however ,liquidparticles have more space between them, so they are not fixed in position