Chemistry · Physical Chemistry

Some Basic Concepts in Chemistry formulas for JEE

Every Some Basic Concepts in Chemistry formula you need for JEE, grouped by concept.

FormulasRevision notes
20 formulas4 concepts
01Mole Concept and Molar Mass02Concentration Terms (Basic)03Stoichiometry and Stoichiometric Calculations04Basic Chemistry Concepts
01

Mole Concept and Molar Mass

2 formulas

Particles from Moles

N=n×NAN = n \times N_A

Relates the number of moles to the total number of particles using Avogadro's constant.

mole-conceptavogadro

Moles from Mass

n=mMn = \frac{m}{M}

Fundamental relationship between mass, molar mass, and number of moles.

mole-conceptstoichiometry
02

Concentration Terms (Basic)

10 formulas

Empirical Factor

n=MmolecularMempiricaln = \frac{M_{molecular}}{M_{empirical}}

The ratio bridging the empirical formula to the molecular formula.

applies whenn must be an integer.
empirical-formulamolecular-formula

Mass Percent

%w=mcomponentmtotal×100\% w = \frac{m_{component}}{m_{total}} \times 100

Calculates the mass percentage of a component within a whole substance.

concentrationstoichiometry

Percentage of Nitrogen (Dumas Method)

%N=2822400×VSTPmsample×100\% N = \frac{28}{22400} \times \frac{V_{STP}}{m_{sample}} \times 100

Calculates the percentage of nitrogen from the volume of N2 collected at STP.

applies whenVSTP must be in mL.
quantitative-analysisorganic-chemistrynitrogen

Percentage of Carbon (Liebig's Method)

%C=1244×mCO2msample×100\% C = \frac{12}{44} \times \frac{m_{CO_2}}{m_{sample}} \times 100

Calculates the mass percentage of carbon in an organic compound based on the mass of carbon dioxide produced during combustion.

applies whenComplete combustion of the organic sample.
quantitative-analysisorganic-chemistrycarbon

Percentage of Hydrogen (Liebig's Method)

%H=218×mH2Omsample×100\% H = \frac{2}{18} \times \frac{m_{H_2O}}{m_{sample}} \times 100

Calculates the mass percentage of hydrogen based on the mass of water produced during combustion.

applies whenComplete combustion of the organic sample.
quantitative-analysisorganic-chemistryhydrogen

Percentage of Oxygen

%O=3288×mCO2msample×100\% O = \frac{32}{88} \times \frac{m_{CO_2}}{m_{sample}} \times 100

Calculates the percentage of oxygen directly by converting it to carbon monoxide, then carbon dioxide.

applies whenDirect estimation method via I2O5.
quantitative-analysisoxygen

Percentage of Phosphorus (Ammonium Phosphomolybdate)

%P=311877×m(NH4)3PO4⋅12MoO3msample×100\% P = \frac{31}{1877} \times \frac{m_{(NH_4)_3PO_4 \cdot 12MoO_3}}{m_{sample}} \times 100

Calculates the percentage of phosphorus from the mass of ammonium phosphomolybdate precipitate.

applies whenPrecipitation using ammonium molybdate.
quantitative-analysisphosphorus

Percentage of Phosphorus (Magnesium Pyrophosphate)

%P=62222×mMg2P2O7msample×100\% P = \frac{62}{222} \times \frac{m_{Mg_2P_2O_7}}{m_{sample}} \times 100

Calculates the percentage of phosphorus from the mass of magnesium pyrophosphate precipitate.

applies whenPrecipitation as MgNH4PO4, followed by ignition to Mg2P2O7.
quantitative-analysisphosphorus

Percentage of Sulphur (Carius Method)

%S=32233×mBaSO4msample×100\% S = \frac{32}{233} \times \frac{m_{BaSO_4}}{m_{sample}} \times 100

Calculates the mass percentage of sulphur from the mass of barium sulphate precipitate.

applies whenComplete precipitation of sulphur as BaSO4.
quantitative-analysiscariussulphur

Percentage of Halogen (Carius Method)

%X=Atomic mass of XMolecular mass of AgX×mAgXmsample×100\% X = \frac{\text{Atomic mass of X}}{\text{Molecular mass of AgX}} \times \frac{m_{AgX}}{m_{sample}} \times 100

Calculates the mass percentage of a halogen from the mass of the silver halide precipitate.

applies whenComplete precipitation of the halogen as AgX.
quantitative-analysiscariushalogen
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03

Stoichiometry and Stoichiometric Calculations

6 formulas

Pressure Correction (Aqueous Tension)

Pdry gas=Ptotal−Paqueous tensionP_{dry\ gas} = P_{total} - P_{aqueous\ tension}

Corrects the total pressure of a gas collected over water by subtracting the aqueous tension.

applies whenUsed when gas (like N2 in Dumas method) is collected over water.
quantitative-analysisgas-lawsdumas

Volume of Gas at STP (Dumas Method)

VSTP=P1V1×273760×T1V_{STP} = \frac{P_1 V_1 \times 273}{760 \times T_1}

Converts the volume of nitrogen collected at experimental conditions to Standard Temperature and Pressure (STP).

applies whenAssumes ideal gas behavior. P1 must be dry gas pressure in mm Hg.
quantitative-analysisgas-lawsdumas

Percentage of Nitrogen (Kjeldahl Method)

%N=1.4×M×2(V−V1/2)msample\% N = \frac{1.4 \times M \times 2(V - V_1/2)}{m_{sample}}

Calculates nitrogen percentage based on the volume and molarity of standard acid neutralized by evolved ammonia.

applies whenApplicable for non-ring, non-azo, non-nitro nitrogen. V is acid vol, V1 is alkali vol.
quantitative-analysistitrationnitrogen

Chloroplatinate Salt Method for Bases

Mbase=n2×(195.2×msaltmPt−409.9)M_{base} = \frac{n}{2} \times \left( \frac{195.2 \times m_{salt}}{m_{Pt}} - 409.9 \right)

Calculates the molar mass of an organic base via ignition of its chloroplatinate salt to a Pt residue.

applies whenn is the acidity of the base. Salt formula usually involves B_2H_2PtCl_6.
quantitative-analysismolar-massjee-advanced

Silver Salt Method for Molar Mass of Acids

Macid=n×(107.9×msaltmAg−107.9)M_{acid} = n \times \left( \frac{107.9 \times m_{salt}}{m_{Ag}} - 107.9 \right)

Calculates the molar mass of an organic acid via the ignition of its silver salt to form an Ag residue.

applies whenn is the basicity of the acid. Assumes quantitative conversion to silver residue.
quantitative-analysismolar-massjee-advanced

Victor Meyer's Method

M=mRTPVM = \frac{m R T}{P V}

Calculates the molecular mass of a volatile liquid by displacing an equivalent volume of air.

applies whenUsed for volatile organic liquids. Assumes ideal gas behavior.
molar-massgas-lawsjee-advanced
04

Basic Chemistry Concepts

2 formulas

Degree of Unsaturation (DOU)

DU=C+1−H2+N2−X2DU = C + 1 - \frac{H}{2} + \frac{N}{2} - \frac{X}{2}

Calculates the number of rings and/or pi bonds in an organic molecule given its molecular formula.

applies whenC = carbons, H = hydrogens, N = nitrogens, X = halogens. Oxygen and Sulfur do not affect DOU.
organic-chemistrystructurejee-advanced

Retardation Factor (Rf Value)

Rf=Distance moved by substanceDistance moved by solventR_f = \frac{\text{Distance moved by substance}}{\text{Distance moved by solvent}}

Measures the relative distance travelled by a compound in chromatography.

applies whenApplies primarily to Thin Layer Chromatography (TLC) and Paper Chromatography. Value is always < 1.
chromatographypurification
Other chapters
ChemistryAtomic Structure49 formulasChemistryClassification of Elements and Periodicity in Properties12 formulasChemistryChemical Bonding and Molecular Structure19 formulasChemistryChemical Thermodynamics34 formulasChemistryEquilibrium40 formulasChemistryRedox Reactions11 formulasChemistryOrganic Chemistry - Some Basic Principles and Techniques16 formulasChemistryHydrocarbons13 formulasChemistrySolutions32 formulasChemistryElectrochemistry26 formulasChemistryChemical Kinetics26 formulasChemistryd- and f-Block Elements46 formulasChemistryCoordination Compounds8 formulasChemistryOrganic Compounds Containing Halogens28 formulasChemistryAlcohols Phenols and Ethers30 formulasChemistryAldehydes Ketones and Carboxylic Acids32 formulasChemistryOrganic Compounds Containing Nitrogen20 formulasChemistryBiomolecules15 formulas

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