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Step 1: we need to find out 39g of liquid benzene is equivalent to how many moles of the liquid.

Moles = mass/molar massmass = 39gmolar mass= 78

Therefore moles of liquid benzene = 39/78 = 0.5 moles

Step 2: Use the equation plus the moles of the liquid benzene to find the moles of O₂ used.

2C₆H₆+15O₂--->12CO₂+ 6H₂O

We see that for every 2 moles of liquid benzene we require 15 moles of O₂ for the reaction. Thus;

If 2 moles benzene needs 15 moles of oxygen,Then 0.5 moles will need 15ₓ 0.5/2 = 3.75 moles of oxygen.

Step 3: Calculate the volume of oxygen required from its moles calculatedThe ideal gas law states that 1 mole of an ideal gas will occupy 22.4 liters at STP(standard temperature and pressure)

Therefore if 1 mole of oxygen occupies 22.4 liters,Then 3.75 moles of oxygen will occupy; 22.4 litersₓ 3.75 moles/1 mole = 84 liters

Therefore 84 liters of oxygen is what is required to completely burn 39g of liquid benzene.

Mass of the total mixture= 22g(benzene) + 122g(CCL4)=144g

Mass % of benzene=(Mass of benzene/Mass of the total mixture)*100=(22g/144g)*100=15.28%Similarly, Mass % of CCL4=(Mass of CCL4/Mass of the total mixture)*100=(122g/144g)*100=84.72%

In general, Mass% of any component(X) in a mixture=(Mass of component(X)/mass of total mixture)*100

To calculate this question:

Step 1: we need to find out 39g of liquid benzene is equivalent to how many moles of the liquid.

Moles = mass/molar massmass = 39gmolar mass= 78

Therefore moles of liquid benzene = 39/78 = 0.5 moles

Step 2: Use the equation plus the moles of the liquid benzene to find the moles of O₂ used.

2C₆H₆+15O₂--->12CO₂+ 6H₂O

We see that for every 2 moles of liquid benzene we require 15 moles of O₂ for the reaction. Thus;

If 2 moles benzene needs 15 moles of oxygen,Then 0.5 moles will need 15ₓ 0.5/2 = 3.75 moles of oxygen.

Step 3: Calculate the volume of oxygen required from its moles calculatedThe ideal gas law states that 1 mole of an ideal gas will occupy 22.4 liters at STP(standard temperature and pressure)

Therefore if 1 mole of oxygen occupies 22.4 liters,Then 3.75 moles of oxygen will occupy; 22.4 litersₓ 3.75 moles/1 mole = 84 liters

Therefore 84 liters of oxygen is what is required to completely burn 39g of liquid benzene.

Well, let me get to your question. So, sulphur dioxide is present in the atmosphere, because of us. When there is a rainfall, the rain droplets which are basically pure H2O get combined with SO2. This leads to the formation of H2SO3. This is a pretty good acid. The colour of Taj Mahal became yellow due to this reason only. The calcium carbonate of the marble reacted with this acid and resulted to the formation of a yellow coloured compound,which got deposited on its surface. This is why the government banned all the nearby factories producing SO2 gas as their waste. Overall, due to SO2 and some other non-metallic gases, water combines with them and forms acid. This leads to decrease in pH of rainwater.

water is good conductor of electricity but in front of it it is written just opposite.similarly plastic is bad conductor of electricity so answer will be just opposite

good conductor of electricity...

2 C6H6 + 15O2 ---------------> 15CO2 + 6H2O

Given,

39 gm of liquid benzene i,e 0.5 mole of benzene

therefore,

Moles of O2 = 15/4

therefore,

Volume at STP = 15/4 X 22.4L

= 84L

Molecular mass of ethanoic acid=60

Molecular mass of benzene=78

Number of moles of ethanoic acid= 2.5/60=0.041Number of moles of benzene= 75/78=0.96153Mole fraction= 0.041/(0.041+0.96153)=0.04

Molality = Number of moles of solute/weight of the solvent (in kg)= 0.041/0.075=0.5466

The density of water become 1 gm/ml at 4 degree Celsius

Hence molarity becomes equal to molality at 277K

option 3 is the answer. Benzoic acids are more acidic than phenols as pka of these carboxylic acid is 3-7 where pka of phenol is 7-10

The statement is false because it's SI unit is Joules per kg or in general, calories/gram.

density of water is = 1g/ml so in 18ml , mass of water is = 18g and moles will be = 18/18 = 1 mol

in other options it is less

option 3

thanks

Works &. Current...are the answer of this question..

a When sulphuric acid is poured on copper plate, hydrogen gas is realeasd.copper+sulphuric acid - copper sulphate+ hydrogen gas

Rutherford concluded from his metal foil experiments that most of an atom is empty space with a tiny, dense, positively charged nucleus at the center that contains most of the mass of the atom. He also concluded that the electrons orbit the nucleus like the planets orbit the sun.

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons.

Atomic radius decreases across a period because valence electrons are being added to the same energy level at the same time the nucleus is increasing in protons. The increase in nuclear charge attracts the electrons more strongly, pulling them closer to the nucleus.

Packing efficiency for bcc arrangement is 68% which represents total filled space in the unit cell. Hence, empty space in a body centered arrangement is 100 – 68 = 32%

Packing efficiency for bcc arrangement is68%which represents total filled space in the unit cell. Hence, empty space in a body centered arrangement is 100 – 68 =32%.

for cubic close packing..100-74=26%

Example of isotopes :1.The three most stableisotopesofhydrogen: protium (A = 1), deuterium (A = 2), and tritium (A = 3).

2. Carbon 12 and Carbon 14 are both isotopes of carbon, one with 6 neutrons and one with 8 neutrons (both with 6 protons).

Ans :- From left to right across a period of elements, electronegativity increases.If the valence shell of an atom is less than half full, it requires less energy to lose an electron than to gain one. Conversely, if the valence shell is more than half full, it is easier to pull an electron into the valence shell than to donate one.

Atomic size gradually decreases from left to right across a period of elements. This is because, within a period or family of elements, all electrons are added to the same shell. However, at the same time, protons are being added to the nucleus, making it more positively charged.

The effect of increasing proton number is greater than that of the increasing electron number; therefore, there is agreater nuclear attraction.This means that the nucleus attracts the electrons more strongly, pulling the atom's shell closer to the nucleus. The valence electrons are held closer towards the nucleus of the atom. As a result, the atomic radius decreases.

Atomic radius decreases across a period because valence electrons are being added to the same energy level at the same time the nucleus is increasing in protons. The increase in nuclear charge attracts the electrons more strongly, pulling them closer to the nucleus.

increase in nuclear attraction. atomic radius decreases with increase in z-effective nuclear charge more the attraction from nucleus,less the size.in a period effective nuclear charge increases on going from left to right.

atomic radius decreases across a period because valence electrons being added

atomic radius decreases across a period because valence electrons being added to the same energy level at the Same time the nucleus is increasing in protons.the increase in nuclear charge attracts the electrons more strongly,pulling them closer to the nucleus.

Given density (d) = 8.55 g/cm³Atomic mass (M) = 93u = 93 g/molWe know, Avogadro number, N= 6.022 × 10²³given lattice is body - centered cubic,so, number of atoms per unit cell (z) = 2we know,\bf{d=\frac{zM}{a^3N}}d=a3NzM​=> 8.55 = (2 × 93)/(a³ × 6.023 × 10²³)=> 8.55 × a³ × 6.023 × 10²³ = 186=> a³ = 186/(8.55 × 6.023 × 10²³)=> a³ = 36.124 × 10^-24=> a = 3.3057 × 10^-8 cm

for BCC unit cell, radius = √3a/4= (√3 × 3.3057 × 10^-8)/4= (1.732 × 3.3057)/4 × 10^-8= 1.431 × 10^-8 cm = 1.431 × 10^-10 m= 1.431 A°

hence, atomic radius of Niobium is 1.431A

Atomic radius patternsareobserved throughout theperiodic table. Atomic size gradually decreases from lefttoright across aperiodofelements. This is because, within aperiodor family ofelements, all electronsareaddedtothe same shell.

Tendency of atoms to lose electrons and form positive ion is known aselectropositivity. In aperiod electropositivitydecreases because of increase in ionization energy along aperiod. While in agroup electropositivityincreases because ionization energy decreases when we move down in agroup.

Here we will get

Zr and Hf exhibit similar propertiesdue to lanthanoid contraction. Electrons present in f subshell didn'tdogood shielding due to which with the increasing atomic number or increasing effective nuclear charge size gets constricted and size of Halfenium and Zirconium becomes almost equal.

The noble gases already have a full set of valence electrons; this means they don't need to bond or attach to other elements to achieve stability. Because of this, they're often referred to as inert, or non-reactive. So, like nobility, the noble gases don't often bond or interact with the general population. Like their name implies, noble gases are gases at room temperature. More specifically, they are odourless, colourless and tasteless gases. They also have low melting and boiling points.

They havesimilar chemical propertiesbecauseisotopesof an element have thesamenumber of electrons as an atom of that element. The electron arrangement is thesameowing tos ame chemical properties. However they have different numbers of neutrons, which affects the mass number.

Chemical properties depend on the electronic configuration of an atom. Since, isotopes of an element have same atomic number or number of electrons or more precisely same electronic configuration hence, isotopes of an element show similar chemical properties.(ii) When Rutherford bombarded fast moving a-particles on gold foil he observed that few a-rays were deflected and very few a-rays re-bounded completely. Then, he concluded that nearly all mass of an atom is concentrated within the nucleus and . most of the space in an atom is empty.

In chemistry, valence bond (VB) theory is one of two basic theories—along with molecular orbital (MO) theory—that use quantum mechanics to explain chemical bonding. According to VB theory, a covalent bond forms from the physical overlap of half-filled valence orbitals in two atoms.

Mechanism of Bonding in VB Theory:

The VB theory describes the formation of covalent bonds from the overlap of atomic orbitals on two different atoms. Because of the overlap, it is highly probable that a pair of electrons are found in the physical region or space where the orbitals overlap.

Heitler and London introduced this theory. This is primarily based on the concepts ofatomic orbitals,electronic configuration of elements, the overlapping of atomic orbitals, hybridization of atomic orbitals. The overlapping of atomic orbitals results in the formation of a chemical bond. The electrons are localized in the bond region due to overlapping.

Valence bond theory describes the electronic structure of molecules. The theory says that electrons fill the atomic orbitals of an atom within a molecule. It also states that the nucleus of one atom is attracted to the electrons of another atom.

= Molar mass of CuSO4*5H2O is 249.6850

= 249.6850 g contains ----- 144 g of O2

= 50 grams contain = 50 * 144 / 249.6850 = 28.8 g.

PV = n RT= (m/M) RTWhere P is pressure, V is volume, n is number of moles R is a constanet and T is the kelvin temperature,m is the mass of gas and M is the molecular weight of the gas.Now we know that

M= dRT /P

=1.15 x .0821 x 300/ 740 /760 = 29.07gmol-1Now take W1is the mass fraction of nitrogen and 1-W1is the mass fraction of oxygenNow we get W1*28 + (1 - W1)32 = 29.07Now solving the above equation we get-4W1= -2.94So W1= 0.70So % of nitrogen is 70 by weight of the airhence option 3 is answer

There is 21% of Oxygen present in 1 Litre of air.

So the total amount of Oxygen is,

=(1x21/100)L

=0.21 L

In Standard pressure and temperature(STP);

1 mole of gas is 22.4 litres in volume,

So the total number of moles present in 0.21 litre is

=(0.21 x 1/22.4)mole

=0.009375 mole

option a

mass of water = density*volume = 1000gm

moles of water = 1000/18mol

concentration of water = 1000/18mol/L

= 55.5 mol/L

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bahot hard hai kisi expert ko pucho

16.66% is the correct answer

The joules unit number 101.33 J converts to 1 l atm, one Litre-atmosphere. It is the EQUALenergyvalue of 1 Litre-atmosphere but in the joulesenergyunit alternative.

In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.