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liduids and gases hoga

Liquids and gases hogaya

nylone,polythene,buna

nylon, polythene,buna

28 h AAP ka Jo question tha us ka

E = hc/(wavelength)

so, for wavelength = 550nm then energy of 1 photon is

E =6.626 x 10-34J·s x 3 x 108m/sec/ (550nm x 10-9m)

E = 3.61 × 10^-19 J

now nE = 10^-17

so, n = 10^-17/(3.61 × 10^-19) = 100/3.61 = 27.7 = 28.

Let atomic weight of x = Mxatomic weight of y = My

we know, mole = weight /atomic weight a/c to question,

mole of xy2 = 0.1 so, 0.1 = 10g/( Mx +2My)

Mx + 2My = 100g -------(1)

for x3y2 ; mole of x3y2 = 0.05

0.05 = 9/( 3Mx + 2My )

3Mx + 2My = 9/0.05 = 9× 20 = 180 g ---(2) solve eqns (1) and (2)

2Mx = 80 Mx = 40g/mol

and My = 30g/mole

Let us consider X metal as Zinc here. Zinc reacts with dil. HCl to form zinc chloride and hydrogen gas.

Zn + dil 2HCl --------- ZnCl2 + H2↑

Here the compound Y is any metal carbonate or metal bicarbonate which reacts with dil. HCl to form salt, water and CO2 gas is evolved. Let us consider here Y as sodium carbonate or sodium bicarbonate.

Na2CO3 + 2HCl → 2 NaCl + H2O + CO2↑

NaHCO3 + HCl → NaCl + H2O + CO2↑

When carbon dioxide is passed through lime water, it turns milky.

Ca(OH)2 + CO2 → CaCO3+ H2O

Hence X is ZincY is sodium carbonate or bicarbonate

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Nitric acid not used in the laboratorypreparation of hydrogen. This is becausenitric acidis a strong oxidising agent, and oxidises hydrogen gas to convert it into the water. sulphuricacidanddilutehydrochloricaciddonotoxidise hydrogen into water hence preferred for the preparation of hydrogen gas.

As equal number of dil HCl and dil NaOH is requiredHence 20 drops are required for neutralisation

Lime is a base with formula CaO and when an acid reacts with it,it results in neutralisation reaction,forming salt and water.No evolution of Carbon dioxide is present in this reaction. Also,other substances being bases also react,but it results in formation of Carbon dioxide as they have more complex formations.

Bottle when filled with water gains 2 gTherefore,Mass of water = 2 gDensity of water = 1 g/cm³

Volume of bottle = Mass of water / Density of water= 2 g / (1 g/cm³)= 2 cm³

Density of oil = Mass of oil / Volume of bottle= (21.76 g - 20 g) / 2 cm³= 0.88 g/cm³

Density of oil is 0.88 g/cm³

Principal focus is a point (on the principal axis) where parallel incident rays meet after reflecting (in mirrors) or refracting (in lenses). It is a fixed point of particular lens/mirror and depends upon its shape. Principal Focus also determines the focal length of the lens/mirror.

Focal lengthThe distance between the centre of a lens or curved mirror and its focus, is called focal length. It measures of how strongly the system converges or diverges light.

Mass percentis used as a way of expressing a concentration or a way of describing a component in a mixture. For asolution, themass percentis expressed as the grams of solute divided by the grams ofsolution, then multiplied by 100 to get apercentage.

Magnesium reacts with hydrochloric acid according to the equation: Mg(s) + 2 HCl(aq) --> MgCl 2(aq) + H 2(g) This demonstration can be used to illustrate the characteristic reaction of metals with acid, a single replacement reaction, or to demonstrate the generation of hydrogen gas.

Zinc reactswith hydrochloric acid toliberate Hydrogen gasas it is more reactive thanHydrogenand hence, displace it. Copper is less reactive when compared toHydrogenand hence cannot displace it. The same can be understood by looking at the activity series of metals.

3 gram of Carbon will react with only 8 gm of oxygen gas to give 11gram of carbon dioxide. 42 gram of oxygen will be left.

law of definite composition states that a given chemical compound always contains the elements in fixed ratio by mass. The ratio is independent of the source and method of preparation.

Fighting fires is complex and dangerous and requires organization and teamwork. At every emergency scene, fire fighters perform specific duties assigned by a superior officer. At fires, they connect hose lines to hydrants and operate a pump to send water to high-pressure hoses. Some carry hoses, climb ladders, and enter burning buildings—using systematic and careful procedures—to put out fires. At times, they may need to use tools to make their way through doors, walls, and debris, sometimes with the aid of information about a building's floor plan. Some find and rescue occupants who are unable to leave the building safely without assistance. They also provide emergency medical attention, ventilate smoke-filled areas and attempt to salvage the contents of buildings.

Wood firesand otherscausedby cloth can be extinguished with water, sand, or other chemicals like infireextinguishers.

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Fire extinguisherswith a Class C rating are suitable forfiresin “live”electricalequipment.

Both monoammonium phosphate and sodium bicarbonate arecommonly usedto fight thistypeoffirebecause of their nonconductive properties.

1) Dry ice2) Solid CO2 is called Dry Ice powder. When it is sprayed over fire, then it immediately vaporizes. It shields fresh air from the burning substance. It is heavier than Oxygen. So CO2 stays closer to the burning substance.

3) There are other substances like : Salt Na Cl, Copper salt power, Barium Chloride powder . They are usable too. They form a crust layer on the top of metals which are burning. Then shield them from Oxygen.

option C ( Both A and B)

Both A and B option C

option (C) is the following question answer.

option C is correct answer

option C is the correct answer

option C is the correct answer

by the following question c option is right

The major criteria for an aldehyde or a ketone to undergo aldol reaction is the presence of alpha hydrogen.As the mentioned compound does not have even a single alpha hydrogen therefore it will not undergo aldol condensation reaction.

Primary structureis when amino acids are linked together by peptide bonds to form polypeptide chains.Secondary structureis when the polypeptide chains fold into regularstructureslike the beta sheets, alpha helix, turns, or loops. ... A picture ofprimary structure of protein.

(3) MO

Sodium and Potassium are the most reactive metals on this earth. They react very explosively with both water and air that is why they are stored in oil.

polyglycolic acid is the answer

Alloys are used instead of the pure metals in the electrical heating devices because they have the less electrical conductivity with the less melting point.

The Alloys does not have any single melting point instead of that they have numerous melting point.

So that’s why the alloys are used in the electrical appliances.

n can take values like 1,2,3..

l can take values from 0 to (n-1)

This means l can’t be greater than n.

Now lets look at all the possible combinations to get n+l=5

They would be-

n=3 l=2

n=4 l=1

n=5 l=0

Now lets look at all cases one by one -

n=3 , l=2

it would mean 3d orbital which can accomodate maximum10 electrons.

Similarly ,

n=4 , l=1

Max. electrons=6

n=5 , l=0

Max. electrons=2

Total adds up to18.

Molecular weight of N2 ~ 14x2 => 28Molecular weight of O2 ~ 16x2 => 32

0.8*28 + 0.2*32 => 28.8

Relative to H2 (~2), this is28.8 / 2 => 14.4

option A is correct

in 2nd orbit the energy is -3.4eV

1 electronvolt=

1.602 × 10-19joule

so, in joules it is ..... -3.4*(1.602× 10^-19) = -5.44× 10^-19 j

thats an easy one use brain

Malleability is the property by which a substance can be beaten into sheets.Gold is the most malleable metal

thnx

Metals are good conductors of electricity, because they have free electrons. These free electrons act as charge carriers in the metallic structure, allowingelectriccurrent to flow through themetal.Metals are good conductors of electricity, because they allowelectriccharge to flow freely through them.

option (d) is correct.

all of four options are correct

Covalent compounds are bad conductors of electricity.

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what you doing today

Examples of liquids which are a good conductor of electricity: 1. Water 2. Salt solution 3. Solution of any strong acid in water

The electricalchargeof particles. The total number of electrons in anatomis always the same as the number of protons in the nucleus. This meansatoms have nooverall electricalcharge.