Image result for classification of matter. matter, pure, mixture, elements, compound, homogenous, heterogeneous

Useful Basic Concepts of Chemistry To Make You Smart


What is chemistry?

Chemistry is a branch of science that deals with the study of the composition, structure & properties of matter.

Chemistry is a branch of science that deals with the study of the composition, structure & properties of matter.

List out the important branches of chemistry

1) Physical Chemistry     2) Inorganic Chemistry 

3) Organic Chemistry     4) Analytical Chemistry.


Importance of chemistry 

  1. Chemistry plays an important role in providing food, cloth & shelter.
  2. It plays an important role in the production of many lives saving drugs.
  3. It plays an important role in the manufacture of fertilizers, insecticides & pesticides.
  4. It plays an important role in controlling pollution.
  5. It plays an important role in the production of superconducting ceramics, polymers, optical fibers, etc.,

Matter

Anything which has mass & occupies space.  It can exist in three physical states i.e. Solid, liquid & gas. It is classified as a Pure substance & Mixture.


AI Explained: Important Things You Need To Know


General characteristics of solid, Liquid & gases

Solid

The particles are held close to each other & there is no freedom of movement. They have definite shape & definite volume.


Liquid

The particles are close to each other, but they can move around. They have definite volume but do not have a definite shape.


Gases

The particles are far apart & their movement is easy & fast. They do not have definite volume & definite shape. They completely occupy the container in which they are placed.

Image result for classification of matter. matter, pure, mixture, elements, compound, homogenous, heterogeneous

Mixture

Image result for classification of matter. matter, pure, mixture, elements, compound, homogenous, heterogeneous

A mixture is the physical combination of two or more substances in which the identities are retained. It is again classified as Homogeneous & Heterogeneous mixtures.


Computer Science: Degrees, Specializations, Coding, Jobs, Programming Languages, Etc.


Homogeneous Mixture

A mixture of two or more components forming a single phase &   composition is uniform throughout. 

Ex:  sugar solution in water.


Heterogeneous Mixture 

This is a mixture in which the composition is not uniform throughout.

Ex: Water & oil. 


Pure Substance

A substance that has a fixed( definite & Constant) chemical composition throughout with definite chemical properties. It is further classified as an element & compound.


Elements

An element consists of only one type of atom.


Compounds

This is formed by the combination of two or more elements in a fixed & definite ratio.

Ex: HNO3


Properties of Matter

It is classified as physical properties & Chemical properties.


Electronics: Courses, Careers, History, CAD, Devices, Components, Design, Etc.


Physical Properties

This can be measured or observed without changing the composition of the substance.

Ex Colour, Odour, melting point, boiling point, density, etc.,

There are seven basic physical quantities.


Chemical Properties

Basic Physics Quantities

Physical QuantityName of the unitSymbol
Lengthmeterm
Mass kilogramkg
Timeseconds
TemperaturekelvinK
Electric Current  ampereA
Luminous Intensitycandelacd
Amount of substancemolemol

Multiples & prefixes used in the SI system

Multiples & prefixes used in the SI system

Length (Meter): It is equal to the distance traveled by light in a vacuum in ¹/₂₉₉,₇₉₂,₄₅₈ second. (300,000,000)

Mass (Kilogram): It is equal to the mass of the international prototype of the kilogram.

Time(Second): It is defined in terms of the radiation frequency at which atoms of the element cesium change from one state to another.

Ampere: The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 X 10-7 N.

Kelvin: The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.

Amount of Substance: The mole(mol) is the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kilograms of carbon12.

Luminous intensity: The candela is the luminous intensity. In a given direction, of a source that emits monochromatic radiation of frequency 540 X 1012 hertz & that has a radiant intensity in that direction of 1/383 watt per steradian.


Going to the Moon: 25 Images That Will Capture Your Imagination


What is the mass of a substance?

The amount of matter present in a substance.


What is the weight of a substance?

The force excreted by gravity on an object.

MassWeight
The mass of a substance is constantThe weight of the substance varies from place to place ( it depends on gravity)
Mass is a scalar quantityWeight is a vector quantity

SI Unit

Volume

cm3 or dm3   1L =1000mL., 1000cm3=1dm3 or 1L, cm3 =mL


Density

kgm-3 , CGS gcm-3


Temperature 

  1. Degree Celsius (oC).
  2. Degree Fahrenheit
  3. Kelvin (K)-SI unit 

Relation between oF to oC: 

Relation between oC to Kelvin: K = oC + 273.15.


Scientific Notation

Scientific notation is a way of expressing numbers that are too large or too small to be conveniently written in decimal form.


Precision

Refers to the closeness of various measurements for the same quantity.


Accuracy

Is the agreement of a particular value to the true value of the results.

Measurements / g
Student A1.951.931.940Precision
Student B1.942.051.995Nor Precision & Accuracy
Student C2.011.992.000Precision & Accuracy

Space Race: Photos That Will Capture Your Imagination


What are significant figures? Give the general rule.

Significant figures are meaningful digits that are known with certainty.

  1. All non-zero digital are significant (Noteworthy or having a particular meaning).
  2. Zeros proceeding to the first non-zero digit (leading zeros) are not significant. 
  3. Zeros between two non-zero digits are significant.
  4. Zeros at the end or right of a number (trailing zeros) are significantly provided they are on the right side of the decimal point.
  5. When the numbers are written in scientific notation the number of digits between 1 & 10 gives the number of significant figures.
  • Round Off: Rounding off means a number is made simpler by keeping its value intact but close to the next number.
  • Rules for rounding the numbers
  1. If the rightmost digit to be removed is more than 5, the preceding number is increased by one.

Ex 2.359 = 2.36,  ( 5 is the preceding number)

  1. If the rightmost digit to be removed is less than 5, the preceding number is not changed.

Ex: 2.344 =2.34.

  1. If the rightmost digit is to be removed is 5 the preceding number is not changed if it is an even number but it is increased by one if it is an odd number.

Ex 6.35 =6.4,  6.25 = 6.2


What is the dimensional analysis Factor label method or unit factor method

The method used to convert units from one system to other while solving problems. 

1 inches = 2.54 cm


State law of Conservation of Mass by Antoine Lavoisier

It states that matter can neither be created nor destroyed.


Voyager Probes: Top 10 Amazing Facts To Make You Awestruck


 Law of definite proportions by Joseph Proust

A given compound always contains exactly the same proportion of elements by weight.


Law of multiple proportions by Dalton 

If two elements can combine to form more than one compound, the masses of the one element that combine with a fixed mass of the other element are in the ratio of the small whole number

 Ex H2 (2g) + O2 (16g)             H2O ( 18g)

Ex H2(2g) + O2 ( 32 g)               H2O2 ( hydrogen peroxide)

The mass of oxygen ( 16 g and 32g ) combined with a fixed mass of hydrogen (2g) bears a sample ratio (16:32 or 1:2).


Law of gaseous Volumes by Gay lussac

When gases combine or are produced in a chemical reaction they do so in a simple ratio by volume provided all gases are at the same temperature & pressure.

H2 (100g) + O2 (50g) gives H2O (100g)  (Hydrogen & oxygen ratio is 2:1).


Avogadro Law by Avogadro

An equal volume of gases at the same temperature & pressure should contain an equal number of molecules.


Dalton’s Theory

  • The matter is made of atoms, which are indivisible. 
  • All atoms of a given element are identical in mass and properties.
  • Compounds are combinations of two or more different types of atoms.

 C + O  ————-> CO (1:1).

  • The chemical reaction is a rearrangement of atoms. 

Molecular Mass

Molecular mass is the sum of the atomic masses of the elements present in a molecule. Ex:  CH4 : ( 1 X 12.011) + (4 X 1.008) = 16.043u


Formula Mass

Formula mass is the sum of the atomic weight of the atoms in the empirical formula of the compound.

NaCl crystal contains huge numbers of Na & Cl. ( 23.0 + 35.5 =58.5u).

( Ionic compound is not a molecule, NaCl crystal contains an equal number of cations & anions They exist in a 1:1 ratio, so the empirical formula is one).

Formula mass is used in ionic solids instead of molecular mass. Why?

Because ionic solids do not exist as a single entity in the solid state.


Life on Mars: The fascinating history of Mars


Atomic mass

It is defined as the mass exactly equal to 1/12th the mass of one atom of carbon-12 isotopes.

atomic mass It is defined as the mass exactly equal to 1/12th the mass of one atom of carbon-12 isotopes.

Note: Avogadro ’s number = 6.022 X 1023


Molar Mass

The mass of one mole of a substance in grams is called its molar mass.


Molar Volume

The volume occupied by one mole of gas at STP is called molar volume.

Molar Mass of water=18.02 gmol-1


Molecular Mass

Is the mass of one molecule of a substance expressed in unified mass (u).

molecular mass Is the mass of one molecule of a substance expressed in unified mass (u).

Empirical Formula

It is the simplest formula that represents the simplest whole number ratio of various atoms present in a compound.

(C6H12O6– Empirical formula of glucose: CH2O i.e 1:2:1 Ratio)


Molecular Formula

It gives the kind and number of atoms of each element present in the molecule of a compound.

Molecular Formula – C6H12O6.


INDIA: 10 FASCINATING GEOGRAPHY FACTS THAT WILL MAKE YOU EXCITED


Stoichiometry

Stoichiometry deals with the calculation of masses (sometimes volumes also) of the reactants and the products involved in a chemical reaction.


Limiting Reagent

It is defined as the reagent which is completely consumed during the reaction and is called the limiting reagent.


Excess Reagent

The reagent that is not completely consumed in a chemical reaction is called excess reagent.


Reaction in solution

Most of the reactions are carried out in a solution state. The concentration of a solution or the amount of substance present in its given volume can be expressed in any of the following ways.

  1. Mass percent or Weight percent
  2. Mole fraction
  3. Molarity
  4. Molality.

Mass Percentage

mass percentage

Mole Fraction

It is the ratio of the number of moles of a particular component to the total number of moles of the solution.

mole fraction number of moles divided by no. of moles of solution

Molarity

It is defined as the number of moles of the solute in 1 liter of the solution.


CHANDRAYAAN 2: VIKRAM’S SENSATIONAL DESCENT TO THE MOON


Molality

It is defined as the number of moles of solute present in 1kg of solvent.


SIGNUP FOR MORE INTERESTING AND EXCITING NEW CONTENT


For more content and updates, FOLLOW US on Social Media

You might want to see Nikola Tesla: Top 10 Inventions to Make You Wonder.

Share this article

Leave a Reply

Your email address will not be published.