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drogen economy" Hydrogen economy is the use of hydrogen as the fuel replacing low CARBON energy petroleum products. It is used as the fuel for VEHICLES. Hydrogen is the abundant and cheapest element which is reacted with "air" in the "fuel cell" to produce ELECTRICITY and water as side product.  (ii) "Hydrogenation": The two hydrogen added across the "double bond"of an alkene in order to form and saturated alkane is CALLED hydrogenation. Hydrogenation can be carried out in presence of "CATALYST" such as "nickel", "platinum" and "palladium", etc. e.g. hydrogenation of oils. (iii) "SYNGAS": SYNGAS is otherwise known as synthetic natural gas. It is used as fuel. This fuel is the mixture of "carbon monoxide", "hydrogen" and rarely "carbon dioxide". (iv) "Water-gas shift" reaction: The reaction of "steam" with "carbon monoxide" to produce "carbon dioxide" and "hydrogen" gas is called "water-gas shift" reaction. It is a "reversible reaction". It is an "exothermic reaction" carried out with catalyst. (v) "Fuel-cell": Fuel cell is an "electrochemical cell", which converts the "fuel energy" into "electricity" through "electrochemical reaction" of ""hydrogen fuel cell" in "presence of oxygen" or other "oxidizing agents"."

the ionisation potential of hydrogen atom = 13.6eV Hence, the change in energy to remove the ELECTRON from N = 2 is given by                                   Since, electron is completely REMOVED from n = 2, so we have the change in energy to be                                                     ΔE = E(∞)-E(2) Therefore substituting all the values in the formulae we get,                                             ΔE = 0-\frac{-13.6}{2^2}                                                    ΔE =\frac{13.6}{4} eV                                                            ΔE = 3.4eV The wavelength of the emitted electron is 3.4eV.

temperature” in thermodynamics denotes the “temperature” at which a “non-ideal” gas “behaves” most LIKE an “ideal gas”.  At Boyle temperature, by setting the “compressibility factor” Z to 1, We GET Where a and b are “Van DER Waals” parameters. This is the “virial equation”.  This temperature is formally defined as the “temperature” for which the “second virial coefficient” equals to 0 and at “this temperature” that the “attractive forces” and the “repulsive forces” reacting on the “gas particles” “balance out”.  In any CASE, when there is lower pressures, the “second virial coefficient” will be the “only relevant” one because the “remaining concern terms” of “higher order” on the pressure. We then have , if p = 0. Then Z is the compressibility factor."

st member of the group always differs from its congeners or the other members of the same group. In group 1 or s block, the first element Lithium (Li) shows some similarities to the second member MAGNESIUM of the same group due to the similarities in the RADIUS ratio of the elements or ionic sizes. LIKEWISE, in group 2 BERYLLIUM (Be) differs from the members of its group. The first element has four electrons in their valence shells and shows the maximum covalency of four whereas other elements show maximum BEYOND four.

ization:Intermixing of "atomic orbitals"of "slightly" different ENERGY and shape and "REDISTRIBUTION" of their "ENERGIES" to form "new orbitals" of "identical shape" and "equivalent energies".Hybridization in Atomic number of P: 15One 's', three 'p', and one 'd' orbitals of same shell participates to give hybrid orbitals with TRIGONAL bipyrmidal shape with bond angles and (ii) Hybridization in Atomic number of S: 16One 's', three 'p', and TWO 'd' orbitals of same shell participates to give hybrid orbitals with octahedral shape with bond angles."

Waals equation:(V - nb) = NRT.  Here a and b are Van der waals  constants.Van der Waals constant “a”: It measures the magnitude of the attractive forces among the molecules of the gas. If the value of “a” is greater than the intermolecular forces of attraction are larger. Hence it exhibits the PROPERTY of REAL gases at high PRESSURE.

on of hydrogen is formed when we use hydrogen GAS in REACTANT side and the PRODUCT which is formed CONSIST of evolution of hydrogen gas therefore hydrogen gas evolution occur because it is less reactive fot eg. zinc + hydrochloric ACID --------------->zinc chloride +evolution of hydrogen

your ANSWER AMMONIA

and XENONS are the NOBLE GASES which R IONS

elongs to P–BLOCK element and and is the FIRST element in the group 13 and present in third period. Its density is and has atomic number 5. Silicon also belongs to P- block element and is the first element in the group 14 and present in the third period. Its density is and has atomic number 14. The electron configuration of  Boron is and Silicon . Since both have two ELECTRONS in 1s orbital, have high melting point and are non metals. So, Boron resembles silicon.

xides" or "acid anhydrides" are "oxides" that react with "water" to FORM an "acid" or reacts with base to form salt. They are oxides in high oxidation states of EITHER non-metals or metals.BASIC oxides are oxides which show fundamental properties as opposed to acid oxides. Reacts to form a base with water or reacts with an acid to make water and salt.reacts with water to NaOHgives base therefore, it is a basic oxide. reacts with water to form perchloric acid which turns blue litmus to red colourIt forms acid, therefore, is an ACIDIC oxide."

is structure" is a "DRAWING" of a "molecule" that illustrates the compound's connectivity and identifies the ""LONE pairs of electrons"" that can be connected to "other molecules".  "Lines" between two atoms in a "Lewis structure" are COVALENT bonds and "solitary pair electrons" are drawn as a "pair of points". In the Lewis structure, each atom must have octet except hydrogen. According to the octet rule, each atom has "eight electrons" in its "valence shell", giving it the same "electron configuration"" as a "noble gas". The "Lewis structure" of "sulphate ION" is as follows."

for filling electrons in orbitals - Aufbau principle "Electrons" are added "one at a time" to the "lowest energy orbitals" available until all the "electrons" of the "atom" which have been taken into account. ACCORDING to the "Aufbau principle", electrons FILL lower energy orbitals first.Pauli's exclusion principle and Hund's rule Pauli's exclusion principle: "No two electrons" in an ORBITAL can have same value for all "four quantum numbers".""Hund's rule": "Pairing of electrons" in an orbital should not TAKE place until all orbitals are "singly occupied". II) Electronic configuration of Copper: Copper electronic configuration -iii)

e to draw "Lewis structure" that obeys the "octet rule". Then we can confirmed the "stable structure". To do this, we will CALCULATE the "formal charges" on the atoms. If the COMPOUND have ZERO formal charge no need to draw extra structure of the compound otherwise we are reduced the formal charge by draw different Lewis structure. The Lewis structure of is as follows.LET's assign the formal charge: Oxygen atom (bonded to H) formal charge = 6 - 4 - 2 = 0 Other oxygen atoms formal charge = 6 - 6 - 1 = -1 Chlorine atom formal charge = 7 - 2 - 3 = +2 Let's try to reduce the formal charges of individual atoms by different connectivity of atoms. Draw another Lewis structure.There are no "formal charges" on the atoms, so it is most stable Lewis structure of "

e structure of is as follows. (ii) A dipole moment is a measure of the separation of two electric charges that are opposite. Moments of dipole are a "vector QUANTITY". The MAGNITUDE corresponds to the charge multiplied by the distance between the chare and the direction from NEGATIVE to positive charge. , the electronegativity is DIFFERENT is in between N -H and N-F. Therefore, these two molecules have different dipole moments. (iii) The DISPLACED values are 0.2D in and 1.5D in respectively "

ven CHEMICAL reaction is as follows From the given, Volume of solution = 50 ML Molarity of NABR solution = 0.06 M From 50 ml and 0.06 M of NaBr moles of BR Now, from 0.003 moles of We get, the moles of Now volume required would be:

the "decomposition reaction" is carried out in the "presence of HEAT" is called "THERMAL decomposition" reaction. Calcium carbonate is called quick lime. "Calcium carbonate" is HEATED heavily to form "calcium oxide" and "carbon dioxide" until it is thermally decomposed. Calcium oxide is "dissolved in water" to form "calcium hydroxide" (limestone). This CAUSES a "MILKY suspension" of "calcium carbonate" to bubble carbon dioxide. (b) If the top of the Chimney of the kiln was closed, very low amount of carbonate is formed because thermal decomposition reaction is carried out in presence of oxygen."

arbecue is normally open. While propane and butane MAY be used in cold COUNTRIES, but propane is preferred because it works better at LOW TEMPERATURES. The reason is that propane has lower boiling point (213 K), remains as gas present in the cylinder despite the cooling produced by the "Thomson effect" during the usage and therefore, ensures a constant supply of gas.  By contrast, butane becomes a liquid in the cylinder due to its higher boiling point (272.5 K) and the cooling produced by the "Joule-Thomson effect", and thus, the gas supply becomes "slower and slower" as the gas is used. ii) Butane is used as a "fuel" in CIGARETTE lighters because at room temperature, it is easily liquefied. iii) Vaseline is a "mixture" of strong alkanes with low points of meting. It can prevent loss of moisture and soft lips and nail cuticles. It is also used in cosmetics and ointments."

py of atomization:It is the "enthalpy CHANGE" when "1 mole" of a substance completely dissociates into gaseous atoms. This value is always positive because during SEPARATION of bonds with HEAT ENERGY all the bond separates and no bond unites. The value does not remain constant as they change with the breakage of bonds.Both (a) and (b) are INDICATES enthalpy change."

has the HIGHEST REFRACTIVE INDEX

bbs free energy of combines "enthalpy" and "entropy" in one value. This energy is associated with a "chemical reactions"" that are useful. It is equivalent to enthalpy minus temperature and SYSTEM entropy. Free energy refers to the amount of "energy available" during a "chemical reaction" to do cellular WORK. Gibbs free energy EQUATION If is "negative", the "forward reaction" is "spontaneous". If is zero, the system is at "EQUILIBRIUM". If is "positive", the reaction is "spontaneous" in the "reverse DIRECTION"."

acting "PER unit AREA" of the surface called is PRESSURE.Mathematically, it can be written as followsFrom the GIVEN mass of air at sea level =Substitute the given value into the pressure formulaLet's convert the units into Pa.  We know,Then, ."

ng to Saytzeff RULE "In dehydrohalogenation reactions, the PREFERRED product is that alkene which has the greater number of alkyl groups attached to the doubly bonded CARBON atoms." For example: The dehydrohalogenation of 2-bromobutane YIELDS two PRODUCTS 1-butene and 2-butene.

d have the identical ionic radii in the ionic compound KF about 1.34 Angstrom. ATOMIC radii of both and are different even though they have the same ionic radii. If POTASSIUM loses an electron, the outermost electron orbit is gone and so the atomic radius REDUCES, therefore when electron gains an electron, its atomic radius increases. If fluorine gains an electron, atomic radius increases DUE to more electrons, therefore Fluorine loses an electron , its atomic radius decreases.

ere is divided into four layers based on the changes in the temperature. The four layers are The Troposphere: First layer above the earth surface, also known as low ATMOSPHERE. The Stratosphere: Second layer, also known as upper atmosphere The Mesosphere: Third layer  of the atmosphereThe THERMOSPHERE: Fourth layer. of the atmosphereThe Exosphere: OUTERMOST space of atmosphere.  The temperature decreases with ALTITUDE in the troposphere, due to the uneven heating of the earth surface. In stratosphere, temperature increases with height since heat is absorbed by ozone layer and is released heating the atmosphere.

is an organic chemical compound, colourless liquid. Its molecular STRUCTURE is . Benzene is explosive and toxic, mixes with gasoline, ETHER and other solvents. The molecular WEIGHT of Benzene is 78.114 g/mol. We can use two methods to determine the molecular mass of Benzene,        ADDING all the Carbon atoms and hydrogen atoms present in ().        Using the Molecular formula =

dot structure is the graphical representation how the electrons are DISTRIBUTED. The geometry of a molecule is predicted using this method. Lewis INTRODUCED symbols to represent the valence electrons in the atoms which are called as Lewis symbols. In Lewis dot structure valence electrons are shown as DOTS surrounding the symbol of atom or ion. The reason to LEARN how to draw Lewis structures helps to predict the number and the type of bonds formed around an atom.

oxyribonucleic acid) and RNA (Ribonucleic acid) have nitrogen in the heterocyclic rings. Nitrogen present in AZO groups, rings, and nitro groups cannot be removed as AMMONIA. Since, during digestion these compounds does not FULLY GET converted into Ammonium sulphate Thus, Kjeldahl METHOD is not suitable to compounds which contain nitrogen in nitro, rings and azo groups and cannot estimate the nitrogen present in DNA and RNA.

y is a "measure" of the LACK of thermal energy of any MECHANICAL work system. It also represents the system's randomness. As randomness INCREASES the system entropy. Entropy of the system is directly proportional to the randomness.Let's predict the sign of entropy CHANGE in the following.Gas at lower pressure has greater randomness than \Delta at high pressure (compressed gas) at the same temperature.Hence, entropy decreases, i.e., ."

the Empirical formula, we can find out the smallest whole number ratio which exists between the elements. Empirical formula and the molecular formula are mathematically related                     Molecular formula = n X empirical formula The molecular formula weight of dinitrogen tetroxide   is 92 g/mol. To get the MOLAR mass, use the molar masses of the individual atoms of Nitrogen and Oxygen Molar mass of Nitrogen is 14.007 g/mol (SINCE it has one atom) Molar mass of Oxygen is  2 × 15.9994 g/mol= 32g/mol (Since it has two atoms) THUS, Empirical formula weight = 14 + 32 = 46g/mol Molecular formula weight = n x empirical formula weight                             46g/mol  = n x 92 g/mol Therefore, n = 2 which is the MOLE ratio of elements in this compound. The molecular formula for your compound is              = → dinitrogen tetroxide.

y is a "measure" of the lack of thermal energy of any MECHANICAL work system. It also represents the system's randomness. As randomness INCREASES the system entropy. "Entropy of the system" is directly proportional to the randomness. Let's predict the sign of entropy change in the following. In the GIVEN chemical REACTION "ammonium nitrate" decomposes into nitrogen GAS, water, and oxygen gas. Here, solid is convert into gas phase. The "randomness" is more in gas phase. Therefore, sign of entropy is positive."

________________Which of the following are OXIDIZING AGENTS and which are REDUCING agents? JUSTIFY your answer with half equations: ✔✔Na_______________________

hode:The following reduction REACTIONS supposed to occur at the cathodeThe reaction with a "higher value" ofoccurs at the "cathode".Therefore, "DEPOSITION of silver" will occur at the "cathode".At anode: The "Ag anode" is "attacked" by ions.Therefore, the "silver electrode" at the "anode" dissolves on to FORM At cathode: The following reduction reactions supposed to occur at the cathode.The reaction with a "higher value" of occurs at the "cathode".Therefore, "deposition of silver" will occur at the "cathode".At anode:Since platinum electrodes are inert, the anode is not attacked by ionsTherefore, ions can be oxidized at the anode.But ions having a lower DISCHARGE potential and get preference and decompose to liberateAt cathode, the following reduction reaction occurs to produce gas.At the anode, the following process are possibleFor the "dilute sulphuric acid" reaction (i) is preferred to produce gas.But, "concentrated sulphuric acid" reaction (II) occurs.At cathode: The following reactions occur at at the cathode.The reaction with a "higher value" of takes place at the "cathode".Therefore, "deposition of copper" will take place at the "cathode".The following oxidation reactions are possible at the anode.At the "anode", the reaction with a "lower value" ofis preferred.But due to the "over-potential" of "oxygen", gets "oxidized" at the "anode" to produce gas."

________________How does dihydrogen REACT with:(i) (ii) C(iii) (IV) (v) ✔✔_______________________

ole MOMENT" is a measurement of the "separation" of "two ELECTRIC charges" that are opposite. Moments of dipole are a "vector quantity". The magnitude CORRESPONDS to the "charge multiplied" by the distance between the charge and the DIRECTION from negative charge to POSITIVE charge."

rice are  carbo-hydrates {hydrogen carbon} so.In chemical reaction defenetly rice pulls .when rice pulls they change to black.         And its also fails 2.4 volts torch bulb filament fails when torch focus PUT  on COPPER metal then torch filament fails by chemical reaction .   And another one is iron and magnet normally attraction at south to north r north to south poll.At the same time its TWO repulsion at south  to south r north to north polls.likes it which chemical apply on copper metal its repulsion iron . And which chemical produce or release high radiation POWER

re FOUR LAWS of THERMODYNAMICS

alytic decomposition reaction is carried out in the presence of CATALYST CALLED CATALYTIC decomposition reaction.Potassium dichlorate undergoes decomposition reaction to form potassium chloride and OXYGEN gas.Molecular weight of From the above reaction,For 3 moles of , we need For 2.4 moles of , we need:== 196 g of

of the balloon = mass of the DISPLACED air - mass of the balloon Radius of the balloon, r = 10 m Mass of the balloon, m = 100 kg Therefore, volume of the balloon ==Now the volume of the displaced air =From the given, Density of air = Therefore, mass of the displaced air = Let w be the mass of HELIUM GAS FILLED into the balloon, Then, pv = RT Or Total mass of the balloon filled with He = 1117 + 100 = 1217 kg Therefore PAYLOAD of the balloon = 5028.6 - 1217 = 3811.6 kg Hence, the payload of the balloon is 3811.6 kg

go down a GROUP the ATOMIC RADIUS increase and electroposivity increase. when we from left to right the radius of the atomic DECREASE because of the nuclear CHARGE by nucleus.

is a measurement of the lack of thermal energy of any mechanical WORK system. It also represents the system's randomness. As randomness increases the system entropy. Entropy of the system is DIRECTLY proportional to the randomness.Let's predict the sign of entropy change in crystallization of copper sulphate from its saturated solution.Copper sulphate CRYSTALS have ORDERED arrangement whereas ions in SOL have greater randomness.Therefore, ΔS