MATTER
Anything that exhibits inertia is called matter.
The quantity of matter is its mass.
Classification of Matter:
Based on chemical composition of various substances.
Elements:
Compound:
Mixture:
PHYSICAL QUANTITIES AND THEIR MEASUREMENT
Fundamental Units:
These units can neither be derived from one another nor can be further resolved into any other units. Seven fundamental units of the S.I. system
Physical quantity | Name of the unit | Symbol of the unit |
Time | Second | S |
Mass | Kilogram | kg |
Length | Meter | m |
Temperature | Kelvin | K |
Electric current | Ampere | A |
Luminous intensity | Candela | Cd |
Amount of substance | Mole | Mol |
Derived Units:
These units are the function of more than one fundamental unit
Quantity with Symbol | Unit (S.I.) | Symbol |
Velocity (v) | Metre per sec | ms-1 |
Area (A) | Square metre | m2 |
Volume (V) | Cubic metre | m3 |
Density (r) | Kilogram m-3 | Kg m-3 |
Energy (E) | Joule (J) | Kg m2s-2 |
Force (F) | Newton (N) | Kg ms-2 |
Frequency (n) | Hertz | Cycle per sec |
Pressure (P) | Pascal (Pa) | Nm-2 |
Electrical charge | Coulomb (C) | A-s (ampere – second) |
MEASUREMENT OF TEMPERATURE
Three scales of temperature
Relations between the scales:
0 K temperatures is called absolute zero.
Dalton’s Atomic Theory:
Precision and Accuracy:
SIGNIFICANT FIGURES
Rules:
Scientific Notation:
Numbers are represented in N × 10n form.
Where,
Examples:
12540000 = 1.254 × 107
0.00456 = 4.56 ×10-3
MATHEMATICAL OPERATIONS OF SCIENTIFIC NOTATION
Multiplication and Division:
Follow the same rules which are for exponential number.
Example: (7.0×103)×(8.0×10-7) = (7.0×8.0)×(10[3 + (-7)]) = 56.0×10-4
Result cannot have more digits to the rite of decimal point than either of the original numbers
(7.0×103)/(8.0×10-7) = (7.0/8.0)×(10[3 - (-7)]) = 0.875×1010 = 0.9×1010
Addition and Subtraction:
Numbers are written in such way that they have same exponent and after that coefficients are added or subtracted.
(5×103) + (8×105) = (5×103) + (800×103) = (5+800)×103 = 805×103
Result must be reported with no more significant figures as there in the original number with few significant figures.
Rules for limiting the result of mathematical operations:
Dimensional Analysis:
LAWS OF CHEMICAL COMBINATION
Law of conservation of mass:
“For any chemical change total mass of active reactants are always equal to the mass of the product formed”
Law of constant proportions:
“A chemical compound always contains same elements in definite proportion by mass and it does not depend on the source of compound”.
Law of multiple proportions:
“When two elements combine to form two or more than two different compounds then the different masses of one element B which combine with fixed mass of the other element bear a simple ratio to one another”
Law of reciprocal proportion:
“ If two elements B and C react with the same mass of a third element (A), the ratio in which they do so will be the same or simple multiple if B and C reacts with each other”.
Gay Lussac’s law of combining volumes:
“At given temperature and pressure the volumes of all gaseous reactants and products bear a simple whole number ratio to each other”.
ATOMIC AND MOLECULAR MASSES
Atomic Mass:
Molecular Mass:
Formula Unit Mass
MOLE CONCEPT
Mole:
Molar mass:
Percentage composition:
Mass percentage of an element in a compound = (Mass of that element in the compound/Molecular mass of the compound)×100
Percentage yield:
EMPIRICAL FORMULA AND MOLECULAR FORMULA
Molecular Formula:
Represents the actual number of each individual atom in any molecule is known as molecular formula.
Empirical Formula:
Expresses the smallest whole number ratio of the constituent atom within the molecule.
Molecular formula = (Empirical formula)n
Molecular weight = n × Empirical weight
also,
Molecular weight = 2 × Vapour density
Limiting Reagent:
The reactant which is totally consumed during the course of reaction and when it is consumed reaction stops.
For a balanced reaction reaction:
A +B → C + D
B would be a limiting reagent if nA / nB>nB/nA
Similarly, A is a limiting reagent if nA / nB<nB/nA
CONCENTRATION OF THE SOLUTIONS
Mass by Mass Percentage:
Volume by Volume Percentage:
Volume of solute per 100 mL of the solution
Volume by volume percentage of solute = [(Volume of solute)/(volume of solution)] x100
Parts per million (ppm) :
The amount of solute in gram per million (106) gram of the solution.
ppm = [(mass of solute/mass of solution)]x 106
Mole fraction:
Ratio of the moles of one component of the solution to the total number of moles of solution
Total mole fraction of all the components of a solution is equal to 1.
For binary solutions having two components A and B
Mole fraction of A
XA = (nA)/(nA+nB)]
Mole fraction of B
XB = (nB)/(nA+nB)]
or XB = 1- XA
Molarity(M):
Number of moles of solute per 1000 mL of the solution.
M = (Number of moles of solute)/(Volume of solution in L)
Molality(m):
number of moles of solute per 1000 gram of the solvent.
m = (Number of moles of solute)/(Weight of solvent in kg)