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ure potential of connected in GALVANIC CELLTHE half-cell reactions and potentials of the SPONTANEOUS reaction are as follows:At Cathode:At Anode:Overall reactionThus the standard electrode potential for the COUPLE is 0.34 VIf OXIDATION = reduction  Then, RHS will equal to We know that, Finally, The electrode potential becomes equal to standard electrode potential when reactants and products ratio is equal.

y Any one cation and anion from the following given salt.(a)CaCO3 (b)BaCl2 (c)ZnS (d)Pb(NO3)2 (e)FeCl3 1.physical characteristic,2.dry and wet test for cation ,3.dry and wet test for anion ,4.confirmatory test for cation and anionHere we take calcium carbonate to identify of cation and anion. You can use other ones .(a) Identification of cation in CaCO3 : here Calcium is cation and carbonate is anion. calcium present in fifth group.Solution of the fifth group precipitate in acetic acid GIVES a white precipitate with ammonium oxalate solution.CaCO3 + 2CH3COOH ---> (CH3COO)2 Ca + H2O + CO2 (CH3COO)2Ca + (NH4)2C2O4 ----> (COO)2Ca + 2CH3COONH4Here, (NH4)2C2O4 is ammonium oxalate and (COO)2Ca is white precipitation of calcium oxalate. flame test : Calcium imparts brick red colour to the flame which looks greenish-yellow through blue glass.Identification of anion in CaCO3 : CO3²-, (carbonate ) is anion in the presence of calcium carbonate. If there is effervescence with the evolution of a colourless and odourless gas on adding DIL. H2SO4 to the solid salt, this indicates the presence of carbonate ION. The gas TURNS lime water milky due to the formation of CaCO3.Na2CO3 + H2SO4 ---> Na2SO4 + H2O +CO2Ca(OH)2 + CO2 ----> CaCO3 + H2OIf CO2 gas is passed in excess through lime water, the MILKINESS produced disappears due to the formation of calcium hydrogen carbonate which is soluble in water.CaCO3 + CO2 + H2O-----> Ca(HCO3)2

keleton of the reaction ASSIGN oxidation numbers for the reaction Identify the redox couples COMBINE the redox couples. Balance all the atoms expect oxygen and hydrogen Balance the charge. Balance oxygen atoms. Make electron gain equivalent to electron lost ADD the HALF reactions TOGETHER Simplify the equation Final equation is

idation STATE of oxidizing agent becomes reduced and oxidation state of reducing agent becomes OXIDIZED.The reaction between water and fluorine is as follows.From the above equation,It is CLEARLY states that  is getting oxidized to And  is getting reduced to HF.Therefore, is reducing agent while HF is oxidizing agent.

m "atomic number" is 3 and the chemical symbol of lithium is “Li”. ELECTRONIC configuration of lithium is The "electronic configuration" of Lithium is EXPLAINED by the BASIS of Aufbau principle. The "Aufbau principle" states that atomic orbitals are filled by electrons in the lowest energy levels in the "ground state" of an "atom or ion" before occupying higher energy levels.  For example, before the second subshell is occupied, the "1s SHELL" is filled.Therefore, Electronic configuration of Li is not  it is in accordance with Aufbau principle.

an be dried with sulfuric ACID if the gas does not have a CHEMICAL effect with acid or reacts with sulfuric acid. HYDROGEN sulfide gas cannot be dried with sulfuric acid because gas is oxidized to SULFUR by sulfuric acid.  Therefore, gas has a chemical effect on acid and therefore, does not REACT with it.

uminium sulphide is a thiol compound that itself has a foul smell and can be detected just by smelling. When damp, it reacts with water in the moisture and releases HYDROGEN sulphide which is also a thiol and a poisonous GAS that emits an EXTREMELY foul rotten egg smell. Hence, it is very important to place aluminium sulphide in sealed containers to prevent its reaction with moisture.  The equation for the above reaction is:(b) Although, aluminium is placed higher than hydrogen in the HIGHLY reactive metals group of electrochemical series, aluminium is more stable in moist air. This is because it rapidly develops a thin and protective layer of a few millimetres thickness of aluminium oxide and this prevents the metal to further REACT with water in the moist air.

an “inert gas” with zero Valency, since its octet is filled completely.  electronic configuration is  and molecular orbital electronic configuration is . THUS, the order of bond becomes nullified since the “number of electrons” in “bonding” and “anti-bonding” ORBITALS is equal. Now, since the bond order becomes zero in a  molecule, it does not exist naturally.ii) Most of the MOLECULES/atoms are diamagnetic but it becomes paramagnetic due to the presence of electrons that are unpaired which induces magnetism. As per the molecular orbital electronic configuration,  has a total of 13 electrons, which results in a single unpaired electron in the molecular orbital, which makes it paramagnetic.iii) The bond-dissociation energy and bond order is related directly. The bond association energy does not differ from bond energy in diatomic molecules.Hence in  and  molecules, the bond order REMAINS the same at and the bond association energy also is same.

adical chain MECHANISM” involves the three steps of “initiation”, "propagation", and "termination". In the initial chain initiation step, radicals are formed. Chain initiation step of halogens is ENDOTHERMIC and involves input energy in the form of heat or light. HENCE, chlorine also gets dissociated homolytically by the action of heat or light in chain initiation step in the FOLLOWING process:The other steps, propagation and termination, take PLACE without any input energy and is exothermic.

dation number of N increases from -2 in to +2 in NO and the oxidation number of Cl decreases from + 5 in to -1 in . HENCE, in this reaction, is the reducing AGENT and is the oxidizing agent. i) Ion-electron method:The oxidation half equation is:The N ATOMS are balanced as:The oxidation number is balanced by adding 8 electrons as:The charge is balanced by adding 8 OH-ions as:The O atoms are balanced by adding 6H2O as:The reduction half equation is:The oxidation number is balanced by adding 6 electrons as:The charge is balanced by adding 6OH- ions as:The O atoms are balanced by adding 3H2O as:The balanced equation can be obtained by multiplying equation (i) with 3 and equation (ii) with 4 and then adding them as:ii) Oxidation number method:Total decrease in oxidation number of Total increase in oxidation number of On multiplying with 3 and with 4 to balance the increase and decrease in O and N, we get:The N and Cl atoms are balanced as:The O atoms are balanced by adding 6H2O as:This is the REQUIRED balanced equation.iii) In the above reaction is the reducing agent and is the oxidizing agent.

ransition metals like LEAD, tin, bismuth, thallium, etc., exhibit inert gas EFFECT, i.e., the ELECTRONS located in the "outermost shell" of the atomic orbital remains UNIONIZED in these metals. Although, the oxidation states of both and is the same at +4, the lower state of oxidation of is more stable which converts to rapidly due to its strong oxidation property. Wherein tin, the state is "more stable" than oxidation state, due to its weak oxidation property.

the carbon-carbon bonds in the benzene molecule are of the same length, and it is known that a single BOND is longer than a double bond. In addition, the bond length (the DISTANCE between the TWO BONDED atoms) in benzene is greater than a double bond, but SHORTER than a single bond

ere, = 5 LITRES and = 10 LitresAt STP = 273 K and = ?We know that,Or

e (P) = 20 ATM Temperature (T) = 300 K Volume of the cylinder (Vc): 2.82 L of water = 2820 Volume of the balloon (Vb): Radius of balloon: Volume of balloon: As per the STP, volume: SUBSTITUTING the formula with the RESPECTIVE values, we have,So, Amount of  used to FILL the balloon: So, The total number of balloons filled: 10

________________What are the OXIDATION number of the underlined elements in each of the following and how do you RATIONALISE your RESULTS:(a) (B) (c) (d) ▶ (e) ▶✔✔✔◀_______________________

a to calculate mass percentage in PARTS per million =On substituting the values:i) Percent by mass: MOLALITY is the CONCENTRATION of the solution by calculating the number of solute moles/kg of the solvent So, Mass of chloroform: 119.38 g/mol Since, the mass percentage of  in 100 g of WATER SAMPLE is 1000 g of water sample will contain:ii) Molality of chloroform:

The density of air is 1/10th of the density of earth's atmosphere and its TEMPERATURE is -10°C.Consider the air BEHAVES as an IDEAL gas and it has UNIFORM composition at STP at surface of the earth.Then and  Hence, = ATMOSPHERIC pressure = 760 mm HgThe pressure at the altitude is 73.2 mm

n skeleton: Assigning oxidation number: IDENTIFY Redox couples: COMBINE into TWO half reactions Balance all atoms Balance oxygen atoms Balance hydrogen atoms Balance charge, ELECTRON gain, and electron LOST Overall equation Simplified equation

pirical formula” is formulated by calculating the NEAREST whole number ratio of the atoms or MOLES present in a compound. In order to formulate the empirical formula, one to follow the following steps, 1. The FIRST step involves the conversion of mass to a number of moles in the element. 2. The next step involves the division of the number of moles present in each element by the "SMALLEST value" and then rounding that value to the nearest "whole number". 3. The rounded value represents the ratio of the moles present in the element. 4. This value is then represented in subscript along with the element's chemical symbol. In the above case,  No. of moles in each element: Na = 0.0887 mol O = 0.132 molDivision and rounding of steps:Adding the numbers to the elements we get:Empirical Formula:

ecular formula of Hydrazine is In the presence of Cu(II) catalyst, HYDROGEN peroxide oxidizes hydrazine to nitrogen.The reaction is highly  exothermic and it is ACCOMPANIED by large INCREASE in VOLUME. Therefore, the mixture provides an upward thrust and is used as a ROCKET fuel. The chemical reaction is given below.

of DIOXYGEN = 70.6 gMolar MASS of dioxygen = 32 g/molWeight of Neon = 167.5 gMolar mass of Neon = 20 g/molWe KNOW,

drogen sulphide reacts with chlorine gas to give solid sulphur and HClBy balancing the equation we get,   i) Oxidation number method:The BALANCED equation is as follows,Oxidation: Reduction: Where +2 state of Sulphur in the reactant gets OXIDIZED to ZERO state in the product and Zero state chlorine in the reactants gets reduced to in the productii) Ion electron method:a) B) C) d) e) f) g) This the final reaction where L.H.s is equal to R.H.Sh) i) This is a best example for redox reaction. Here, chlorine is the oxidizing agent which gets reduced itself to HCl and is the reducing agent which gets oxidized to sulphur.

of CONTAINS MOLECULAR MASS of = 180 G/mol9 g of = ?

name of the compound is hydrogen peroxide and molecular formula is ii) Hydrogen peroxide ACTS as oxidizing as well as reducing agent in both acidic and basic solution because oxidation state of hydrogen peroxide is -1, therefore, it can be reduced to hydroxide ion or oxidized to oxygen.iii) Hydrogen peroxide should be stored in fireproof rooms where it is PROTECTED from direct sunrays.iv) Uses:♦ Hydrogen peroxide is used as bleaching agent.♦ Used in manufacturing of INORGANIC chemicals.♦ Mainly used to produce POLYURETHANE, epoxides, and propylene oxide.♦ Used in pharmaceuticals.♦ 93% of Hydrogen Peroxide is used as rocket FUEL.

t the same TEMPERATURE, the value of for reverse reaction is c) is same for the reaction because the temperature REMAINS same.At constant temperature, is constant. In this CONDITION will not change.In case of endothermic reaction, value increases with INCREASE in temperature. The given reaction is an endothermic reaction. Hence, as the temperature increases the value of is also increased.

e given, = 12 BAR = 27°C + 273 = 300 K = 14.9 bar = ?According to the PRESSURE TEMPERATURE law,Substituting the given values,Temperature in centigrade = 372.5 - 273 = 99.5°C  Therefore, the cylinder will be at 99.5°C.

at 25°C the concentration of in acidic solutionWe KNOW that,At room temperature,It is GIVEN that, , hence So, But, So, PH of the solution is 9.

At 25°C, the concentration of in the SOLUTION We KNOW that, At room temperature, It is GIVEN that, So, But PH + pOH = 14 So, pH of the solution is 5.

t 15°C and 900 mm pressure 0.4 gram of gas occupied 3280 mlConsider, if the pressure is changed to 1300 mm at constant temperatureWe KNOW that, PV = nRTThen,  Here, temp = 15°C (15+273); pressure = 1300 nm; MOLAR mass = 0.4 g; and R = 8.314Density of the gas = 0.2172 g/L

ng to the Dalton's LAW, the total pressure in the cylinder is the SUM of the pressure of the NITROGEN and the WATER vapour.From the given,  Total pressure = 600 = 23.8Substitute the given values 600 = + 23.8 = 576.2 mmHgAccording to the BOYLE's law pressure of nitrogen will be doubled.Therefore,Total pressure = 1152.4 + 23.8Total pressure = 1176.2 mmHg

rection of the net chemical REACTION DEPENDS upon the reaction constant and equilibrium constant .Hence, If the reaction is at equilibrium state.If the reaction will take a forward DIRECTION.If the reaction will take a backward direction.In the above case, Molecular Concentration (M) of reactants and products:SUBSTITUTING the values:Comparing SINCE the reaction constant is < than equilibrium constant  , the reaction will move in the forward direction and the reactants get converted into the products.

two oxidation states shown by gallium is +3 and +1 and this is mainly due to inert PAIR effect. Of the two oxidation state exhibited, +3 oxidation state is more STABLE and +1 oxidation state is least stable. Hence, disproportionation OCCURS by gallium in aqueous solution to form most stable +3 oxidation state.The disproportionation reactions of gallium in aqueous medium is as follows,i) Both and shows +1 and +3 oxidation states, but the inert pair effect is more dominant. So +3 oxidation state is more stable compared to +1 oxidation state for And in the case of , the +1 oxidation state is more stable compared to +3 oxidation state. So, in aqueous solution, LESS stable +3 of under GOES disproportionation to form more stable +1 state. Whereas, in , +1 is most stable oxidation state, so it does not undergoes disproportionation reaction.Similar, answer for third question also. Because undergoes disproportionation reaction to form +3 oxidation state to +1 oxidation state, whereas, the +1 oxidation of is stable as it does not undergo disproportionation reactions.

ng to periodic table, the ELEMENTS Zinc, Gallium, and Potassium belongs to 4th period.  The energy needed to remove the electrons present in the outermost shell of atoms are called ionization energy. The first ionization energy is very minimum energy compared to the SECOND and third ionization energy. Because, there requires minimum energy to remove or eject the electron from the outermost shell which are loosely bond to the NUCLEUS.  The ionization energy of Potassium = 418.7 KJ/mol The ionization energy of Zinc = 906.41 KJ/mol The ionization energy of Gallium = 578.8 KJ/mol USUALLY, from left to right along the period the ionization energy increases. But the ionization energy of gallium is lower than zinc because Zinc has a completely filled electronic configuration whereas gallium which STARTS filling p-orbitals . Because of completely filled configuration, zinc is stable and requires higher ionization energy whereas gallium is yet to fill its p-orbitals, so it has lower ionization energy compared to zinc.

t character: An electron is shared MUTUALLY by two atoms, in between these two atoms an ionic bond is PRESENT. In the periodic table, as we go down the group, the size of the halogens increases whereas its electro negativity decreases down the group. The increase in covalent character is in the order of MF < MCI < MB < MI where, M refers to any ALKALI metals.

y: It is a term USED to measure "disorder or randomness". Positive entropy: It DENOTES the probability required to make PARTICULAR state DEPENDS on the number of ways in which that arrangement. Entropy completely depends upon the microstates of the system, increase the microstates of the system and increase the entropy and also increase the positive value of S.

on number is the total number of electrons GAINED or lost by an atom in ORDER to form a bond with another atom.The oxidation number is zero for atoms that contains only ONE element. For iodine molecule, the oxidation number is zeroHydrogen is +1 oxidation stateFor HI = -1For = +7For ICL = +1The TREND of increase in oxidation number for the given elements is .

: NaPercentage composition: 14.31Atomic mass: 23Relative number of atoms: Simplest ratio: Element: SPercentage composition: 9.97Atomic mass: 32Relative number of atoms:Simplest ratio: Element: HPercentage composition: 6.22Atomic mass: 1Relative number of atoms: Simplest ratio: Element: OPercentage composition: 69.5Atomic mass: 16Relative number of atoms: Simplest ratio: The empirical FORMULA = Empirical formula mass = MOLECULAR mass = 322Whole of the hydrogen is present in the form of water. THEREFORE, 10 water MOLECULES are present in the molecule. Therefore, molecular formula =

e givenT = 27°C = 27 + 273 = 300 K= 227°C = 227 + 273 = 500 KV = 0.1 = 1 litre   = ?  The volume of the FLASK is 66 mL

@ STP = 89.6 ML

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electrolytic refining, impure metal is made anode and a thin strip of pure metal M is made cathode and the ELECTROLYTE USED is the SOLUBLE SALT of Metal M which is to be refined.