Physical Parameter

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Physical parameter

Name of the Physical Quantity: Mass and Weight 

> It is fundamental unit having SI unit kilogram (kg).

> The mass of a body does not vary as its position changes.

     The weight of a body is result of the mass and gravitational attraction. 

      So, it varies with position because the gravitational attraction of the earth

      for a body varies.  

> Weight is a force, while mas is the property that determines the strength of this force.

> It is extensive property.  

       1 kg = 1000 g  

       1 metric ton = 1000 kg  

Atomic Mass

•  It is the mass of an atom. The atomic masses are expressed in atomic mass unit (amu).
• 1 amu = A mass exactly equal to one twelth of the mass of one carbon - 12 atom.
• 1 amu = 1/12 X mass of one C-12   

Name of the Physical Quantity: Volume

          > It is the amount of space occupied by a three dimensional object.

          > SI unit of volume is (meter) ³ or m³. Common unit is liter (L).

          > 1 L = 1 dm³ = 1000 mL = 1000 cm³               1000 L = 1m³

                > A volumetric flask is used to prepare a known volume of a solution.

          > In thermodynamics, the volume of a system is an important extensive                      parameter for describing its thermodynamic state.

          > The specific volume, an intensive property, is the system's volume per unit             of mass.

          > Volume is a function of state and is interdependent with other thermodynamic                  properties such as pressure and temperature.

Let's Know it, WHY?

 

Organic farming food is good for health. WHY?

    Because, in organic farming there is little or no use of chemical fertilizers, pesticides and                 herbicides. Therefore, there is no toxicity due to pollution of crop plants, soil, water or air. 

Physical Parameter- Length, Volume and Density

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Physical parameter

Name of the Physical Quantity: Length

> It is fundamental unit having SI unit meter (m).

> nanometer (nm) [1 nm = 10^-9 m] pico meter (pm) [1 pm = 10^-12 m]

> Length is a measure of distance.

> Length is the measure of one spatial dimension, whereas area is 

    a measure of two dimensions (length squared) and volume is 

     a measure of three

     dimensions (length cubed).

10 mm = 1cm

100 cm = 1 m

1000 m = 1 Km

Name of the Physical Quantity: Volume

 > It is the amount of space occupied by a three dimensional object.

 > SI unit of volume is (meter) ³ or m³. Common unit is liter (L).

 > 1 L = 1 dm³ = 1000 mL = 1000 cm³          1000 L = 1m³

 > A volumetric flask is used to prepare a known volume of a solution.

 > In thermodynamics, the volume of a system is an important extensive property.
 >The Specific Volume is intensive property.

 > Volume is a function of state and is interdependent with other 

        thermodynamic properties such as pressure and temperature.

Name of the Physical Quantity: Density

> It is mass per unit volume. SI unit of density is kg m^-3.

>The density also known as specific mass, of a substance is its 

      mass per unit volume.

> The symbol most often used for density is ρ (the lower case 

     Greek letter rho), although the Latin letter D can also be used.

> Osmium and iridium are the densest known elements at 

       standard conditions for temperature and pressure.

>  "Relative density" or "Specific gravity", i.e. the ratio of the density

      of the material to that of a standard material, usually water.          

   Thus a relative density less than one means that the substance 

     floats in water.

> The density of a material varies with temperature and pressure. 

   Increasing the pressure on an object decreases the volume of the 

    object and thus increases its density. Increasing the temperature 

    of a substance (with a few exceptions) decreases its density by

    increasing its volume. In most materials, heating the bottom of 

    a fluid results in convection of the heat from the bottom to the top, 

    due to the decrease in the density of the heated fluid. This causes

    it to rise relative to more dense unheated material.

>  Density is an intensive property in that increasing the amount of

     a substance does not increase its density; rather it increases its mass.

${\displaystyle \rho ={\frac {m}{V}}}$

 Irfan Bashumiya Pathan

Shamsul Uloom Urdu High school & Higher Secondary School, Osmanabad. (MH)

https://irfan2029.blogspot.com/

Physical Parameter-Temperature

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Physical parameter

Name of the Physical Quantity: Temperature

> Temperature is a measure of the hotness or coldness of an object.

> The SI unit of temperature is K (Kelvin).

> A flow of heat energy from high temperature object to lower 

     temperature object.

> The lowest theoretical temperature is absolute zero, at which no 

    more thermal energy can be extracted from a body. 

    The absolute zero, defined as 0 K, is approximately equal 

       to −273.15 °C, or −459.67 °F.

> In thermodynamic terms, temperature is an intensive variable.

> A negative temperature is one below the zero-point of the scale used.

          For example, dry ice has a sublimation temperature of −78.5 °C 

          which is equivalent to −109.3 °F.

> Temperature is measured with a thermometer.

> There are three common scale to measure temperature,

          1. Kelvin (K) 2. Degree Celsius (⁰C) 3. Degree Fahrenheit (⁰F)

> Relation between two scales:

                ⁰F = 9/5 (⁰C) + 32  and   K = ⁰C + 273.15

Irfan Bashumiya Pathan

Shamsul Uloom Urdu High school & Higher Secondary School, Osmanabad. (MH)

https://irfan2029.blogspot.com/

Benzene

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Benzene

Name of the Substance: Benzene

Chemical name of Substance: 

Cyclohexa-1,3,5-triene; 1,3,5-Cyclohexatriene.

It also called phene and it is called phenyl group.

Chemical Formula: C₆H₆.

Chemical Structure:

>The structure contained a ring of six carbon atoms with alternating single          and double bonds.

> It has trigonal planar structure.

> It has high degree of unsaturation.   

> Benzene is a hybrid of various resonance structures.

> It has sp² hybridization structure.  

> 4n + 2 = number of π electrons.    

                                                                                         

Physical Properties:

>Molar mass 78.114 g mol^-1

>It is colorless liquid.

>It has aromatic odor.

>It has density 0.87 g cm^-3.

>It has melting point5.53 ^oC and boiling point 80.1 ^oC.

>It is soluble in organic solvent.  

>It has zero dipole moment.

Reactivity: Directive influence of a functional group in mono substituted benzene.

    1. Ortho and para directing groups –Cl, - Br, -OH, -O-CH₃,  

                                                         -NH₂, -HR, -CH₃,   -C₂H₅,   -R            

     2. Meta directing groups: -NO₂, -NH₃, -CN, -COH, -COR,                                                                     -COOH, -SO₃H.

Sources: Coal-tar and petroleum are the two large scale sources of                                        benzene.   

Uses: 

1. Benzene was frequently used as an industrial solvent, 

     especially for degreasing metal. 

     As its toxicity became obvious, benzene was supplanted

      by other solvents, especially toluene (methylbenzene), 

         which has similar physical properties but is not as carcinogenic.

      It might be considered “the mother of all carcinogens”.

 2. As a gasoline (petrol) additive, benzene increases                                                     the octane  rating and reduces knocking.

 3. Benzene is used mainly as an intermediate to make other                                     chemicals, above all ethylbenzene, cumene, cyclohexane,                                      nitrobenzene, and alkylbenzene.

Irfan Bashumiya Pathan

Shamsul Uloom Urdu High school & Higher Secondary School, Osmanabad. (MH)

https://irfan2029.blogspot.com/

Glass

GLASS

Name of the Substance: Glass

Chemical name of Substance: Any non-crystalline (amorphous) solid, Super cooled                                                   liquid.

Chemical Composition: It is compound silica (silicon dioxide, or quartz), the primary                                       constituent of sand. Soda-lime glass, containing around 70%                                       silica, account for around 90% of manufactured glass.

Chemical             composition,                            wt%

74 SiO2, 13 Na2O, 10.5 CaO, 1.3 Al2O3, 0.3 K2O, 0.2 SO3, 0.2 MgO, 0.01 TiO2, 0.04 Fe2O3

                          

Chemical Structure: On cooling molten silica quickly, a random organised network                        of these tetrahedra are formed, linked at their corners, to give an                        amorphous material known as vitreous silica.

           

                                  

 Physical Properties:

1.     Optical glass typically has a refractive index of 1.4 to 2.4

2.     It has ability to refract, reflect, and transmit light following geometrical optics.

3.     Glass transparency results from the absence of grain boundaries which diffusely scatter light in polycrystalline materials.

4.     The density of glass varies with chemical composition with values ranging from 2.2 grams per cubic centimetre (2,200 kg/m³) for fused silica to 7.2 grams per cubic centimetre (7,200 kg/m³) for dense flint glass.

5.     It is most viscous solid.

Reactivity

1.     Glass is typically inert, resistant to chemical attack, and can mostly withstand the action of water

2.     Glass will corrode or dissolve under some conditions. The materials that make up a particular glass composition have an effect on how quickly the glass corrodes. Glasses containing a high proportion of alkali or alkaline earth elements are more susceptible to corrosion than other glass compositions.

.

 Uses:

1.     It has widespread practical, technological, and decorative use in, for example, window panes, tableware, and opticsGlass has been traditionally used for vessels: bowls, vases, bottles, jars and drinking glasses.

2.     It has also been used for paperweights and marbles.

3.     Glass can be colored by adding metal salts or painted and printed with vitreous enamels, leading to its use in stained glass windows and other glass art objects.