Explore topic-wise InterviewSolutions in .

cheers! it was so easy...

a. Physical b. Physical c. Chemical d. Chemical

a.physicalb.physicalc.chemicald.chemical

In liquids andgases convection takes placebecause the hotter, low-density fluid risestakingthe heat energy with it - this is called aconvectioncurrent. The bigger the surface area of an object the more air can move round it inconvectioncurrents and the faster it will cool.

TheRosenmund reductionis a hydrogenation process in which an acylchloride is selectively reduced to an aldehyde. The reaction was named after karl roseemund who first reported it in 1918.

This reaction, a hydrogenelisis , is catalysed by palladium on barium sulphate, which is sometimes called theRosenmund catalyst. Barium sulfate has a low surface area which reduces the activity of the palladium, preventing over-reduction. However, for certain reactive acyl chlorides the activity must be reduced further, by the addition of a poison. Originally this was thioquianthrene although thiourea has also been used.

Deactivation is required because the system must reduce the acyl chloride but not the subsequent aldehyde. If further reduction does take place it will create a primary alcohol which would then react with the remaining acyl chloride to form an ester.Rosenmund catalyst can be prepared by reduction of palladium(II) chloride solution in the presence of BaSO4. Typical reducing agent is formaldehyde.

Rosenmund Reduction is an organic chemical reaction in whichthe acid chloride is converted to aldehydesby using hydrogen gas passed over palladium-on-carbon poisoned with barium sulfate. This reaction is named after a German chemistKarl Wilhelm Rosenmund.

In order to prevent further hydrogenation, catalyst is mixed with a poison. Catalytic hydrogenation of acid chlorides allows the formation of aldehydes

Summary:

The Pd catalyst must be poisoned, for example with BaSO4, because the untreated catalyst is too reactive and will give some overreduction. Some of the side products can be avoided if the reaction is conducted in strictly anhydrous solvents.

The reaction is catalysed by palladium on barium sulphate, which is sometimes called the Rosenmund catalyst. Barium sulphate has a low surface area which reduces the activity of the palladium, preventing over-reduction

I mixed and it forms Hydrogen

2Al + 6H2O ---> 2Al(OH)3 + 3H2Al(OH)3 + NaOH ---> NaAlO2 + 2H2O

Final product obtained is Sodium aluminate ( NaAlO2 )

The narrator voluneeter to do packing because he thought he was a best packer and he felt proud of his packing and wanted to prove it

The narrator believed that he knew more about packing than any other person .He thought that nobody was good at packing

The number of muscular heart in earthworm for blood circulation is 5

a)-9,-13,-17b)-10,-12,-14c)-5,-10,-15f)1,4,7

The Beer-Lambert law states that the quantity of light absorbed by a substance dissolved in a fully transmitting solvent is directly proportional to the concentration of the substance and the path length of the light through the solution.

Because Beer's law states this, it means we can both calculate the concentration of a solution by using the absorbancies, or plot a graph of various concentrations, align them to their correct absorbencies, and use a colorimeter to find the concentration of an unknown solution

The law states that:

A(λ) =e(λ)lc.The proportionality constante(λ) is called the absorptivity of the substance at the wavelengthλ.e(λ) is called the molar absorptivity if the concentration is measured in moles/liter.

The absorbance is inversely proportional to the transmittence of the solution

Dobereiner'sLaw ofTriads.Dobereiner, in 1817 suggested a relationship between the properties of elements and their atomic weights. ...Example: If we take lithium, sodium and potassium, the atomic weight of sodium is the mean of the atomic weights of lithium and potassium i.e., (7+ 39)/2 = 23.

All alkali metals form various oxides, hydroxides, carbonates and nitrates. They are hence, known as the most reactive elements as they have the weakest nuclear charge in the respective period. They have the tendency to lose their one valence electron in the last shell and form strong ionic bonds with their anions.Let’s, one by one study the characteristics of the compound of the alkali metals.

Forming Oxides and Hydroxides

The property of alkali metals allows their oxides, their peroxides and their super-oxides to dissolve in water quite readily. Such dissolving in water produces corresponding hydroxides which are basically very strong alkalis. Certain examples in the form of a chemical equation that display such phenomenon are as follows:

2Na + 2H2O → 2NaOH + H2

Na2O +2H2O→ 2NaOH

Na2O2+2H2O→ 2NaOH + H2O2

2KO2+2H2O→ 2KOH + H2O2+ O2

The alkali metals tend to combine directly with different halogens under appropriate conditions, thus forming halides of the general formula MX. Examples that demonstrate the formation of such halides are as follows:

M2O + 2HX → 2MX + H2O

MOH + HX → MX + H2O

M2CO3+ 2HX → 2MX + CO2+ H2O

All alkali metals form various oxides, hydroxides, carbonates and nitrates. They are hence, known as the most reactive elements as they have the weakest nuclear charge in the respective period. They have the tendency to lose their one valence electron in the last shell and form strong ionic bonds with their anions

Alkali metals: Na, K, RB, Cs(4 alkali metals).Please hit the like button if this helped you

thanks

the correct answer is 165

molecular mass of mgo is 40g so in. i-2 moles are thereii-1/4 mole

molecular mass of mgo is 40g so in. 2moles are there1/4 mole

1. 2 moles2. 1/4 mole

dipole-induced dipole attractionis a weakattractionthat results when a polar moleculeinducesadipolein an atom or in a nonpolar molecule by disturbing the arrangement of electrons in the nonpolar species.

Dipole-Induced Dipole Forces

A dipole-induced dipole attraction is a weak attraction that results when a polar molecule induces a dipole in an atom or in a nonpolar molecule by disturbing the arrangement of electrons in the nonpolar species.

a non polar molecule may be polarized by the presence of a polar molecule near it therefore a induced dipole movement generate a non polar molecule. the interaction between them is called dipole induced dipole interaction.generally, non polar molecules are noble gases

hi

hi nhi answer brao

sure I'm finding

okk plz

ok

you are study in 11th standard

yes

oh good !!

from where do you live

plz answer batao fir baat karna

ok

can you send me photo again

it is not loading

6.02×10^3 moles

no

ans. h 2.4 × 10 ^ 25

or 6.02 ×10^56

tu kaha jara

ok soooory....

Since density of water is 1 gm/cc, 72 ml corresponds to mass m =72 g of water.

so, no. of moles corresponding to 72 g = m/A = 72/18=3, where A is molecular wt (water =72 g)

Now, 1 mole of water contains 6.022*10^23 molecules of H2O and

one molecule of H2O contains 10 electrons (i.e. There are 8 electrons in oxygen and 1 from each hydrogen so a water molecule has 10 electrons).

Hence, total no. of electrons present in 72 ml of water =3*10 * 6.022*10^23

= 6.022*10^24*3

= 18.066*10^24

pooja u r also wrong

ok

I'm pooja

im not saying to u

are u angry

no

q

I think so

okkk

where do u live

tujhe ky karna h me kaha bhi rhu

Please do not use this forum for conversartions irrelated to studies

yaar bye sorry

okktell to jatin aldo

okkk

tell Richa also

just go to hell

Please

u first stsrted the conversation

I think you are living in a hell

uuhh! I asked related to your question

pooja plz help

give ans. for this question

POOJA plz help

POOJA.. ..:-)

where r u pooja

in the hell

plzz dont use this words to her

Here we will use the the concept of density of water = 1g/ccD=M/V1 g/ml = M/72 mlM= 72 gmoles of water = mass/molar mass = 72/72 = 11 mole of water contains = NAmoleculestotal electrons in water = 2(H) + 8(O) = 101 molecule of water contains = 10 electrons1 mole water contains = 10 * NAelectronsNA= Avogadro’s number

= 6.022 × 10^24

2.4×10^25 is the answer

Hope so it is right :-)

thnx

Welcm richa

Firstly Write Balanced Chemical Equation In these questions.

6BaCl2 + 4Na3PO4 ==>2Ba3(PO4)2 + 12NaCl

In these Question You Need To find Limiting Reagent.

Now See Balance Equation

For Every 6 moles of BaCl2 4 Moles of Na3PO4 are required

For every 1 mole of BaCl2 4/6 moles of Na3PO4 required.

For 0.5 moles of BaCl2=(4/6)×0.5=0.3333 moles of Na3PO4 are required.

But we have Only 0.2 moles Of Na3PO4 are given,so it is limiting reagent.

Now Coming to the question,

4 Moles of Na3PO4 will give out 2 moles of Na3(PO4)2

1 mole of Na3PO4=2/4 moles of Na3(PO4)2

0.2 moles of Na3PO4=1/2×0.2=0.1

An antiseptic is a substance that inhibits the growth and development of harmful microorganisms, such as those that cause disease. Antiseptics restrain the development of germs that cause disease.

the answer is d. (2) and (4) both sublimation and evaporation takes the heat away from the surface

please explain with steps..

Tq so much

As pressure is inversely proportional to volume,it is increased 4 times.so 8 atm.let me know if there is a catch.

The salt is Baking Soda i.e., Sodium bi carbonate. Na2CO3+CO2+H2O→2NaHCO3

Uses of Baking Soda :(i) It is used as an antacid as it reduces the acidity in the stomach. (ii)Due to the formation of soapy foam, it is used in fire extinguishers

Like if you find it useful

The answer is sodium bicarbonate (NaHCO3)

the equation for its formationNaCl + H2O + CO2 + NH3= nh4cl + NaHCO3

the two uses are:-->used as an antacid-> used as fire extinguisher.

Diffusion is net movement of anything from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in concentration. The concept of diffusion is widely used in many fields, including physics, chemistry, biology, sociology, economics, and finance.

Diffusion is the movement of a substance from anarea of high concentrationto anarea of low concentration.

Diffusion happens inliquidsandgasesbecause their particles move randomly from place to place.

Diffusion is an important process for living things; it is how substances move in and out of cells.

Diffusion is the process of moving of particles from high concentration to low concentration.

XCl2 means X has valency 2 as Cl has valency 1.Valency of Sulphate - 2 Hydroxide-1 So ,formulae needed are XSO4 and X(OH)2.

option a.. with bond order 3

Chromium metal is electroplated on bathroom fittings.It has shiny appearance, does not corrode easily and resists scratches. So that is why it is used in electroplating.

Chromium is used to plate bathroom fitting because it prevents them from corroding and getting scratched. However, objects are not made with Chromium because it is a very expensive metal.

thanks

option 1 is the correct answer of the given question

option 1is correct answer

3 is the right answer

3 is the correct answer to that question

Air is a mixture and not a compound because:

1. Air can be separated by physical means which isn't possible in compounds.

2. Air is heterogenous, as its composition varies from time to time.

3. Air can be prepared by mixing gases in a proportion which is present at a place. This is a physical process as there is no energy being formed.

option b seems to be the most correct. it will form sigma bond.

ya man thanksss

i) The Tyndall effect is the scattering of light as a light beam passes through acolloid. The individual suspension particles scatter and reflect light, making the beam visible.

The amount of scattering depends on thefrequencyof the light anddensityof the particles. As with Rayleigh scattering, blue light is scattered more strongly than red light by the Tyndall effect. Another way to look at it is that longer wavelength light is transmitted, while shorter wavelength light is reflected by scattering.

ii)Solubilityis the property of asolid,liquidorgaseouschemical substancecalledsoluteto dissolve in a solid, liquid or gaseoussolvent. The solubility of a substance fundamentally depends on the physical and chemical properties of the solute and solvent as well as on temperature, pressure and presence of other chemicals (including changes to thepH) of the solution. The extent of the solubility of a substance in a specific solvent is measured as thesaturationconcentration, where adding more solute does not increase the concentration of the solution and begins to precipitate the excess amount of solute.

b. Some facts about water as a compound 1) Its constituents Hydrogen and oxygen are always present in it. 2) Its properties are different from its constituent elements(hydrogen and oxygen) 3) Its constituents cannot be separated by simple physical means but requires chemical methods and it has fixed boiling and freezing point.

c. TheTyndall effectis the scattering of light as a light beam passes through a colloid. The individual suspension particles scatter and reflect light, making the beam visible. As with Rayleigh scattering, blue light is scattered more strongly than red light by theTyndall effect.

d. Newton's laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces.

a part not solve please solve the numerical

Brine is a high-concentration solution of salt in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% up to about 26%. Lower levels of concentration are called by different names: fresh water, brackish water, and saline water.