Chemistry Podcast

Sunday, 14 May 2017

Chemistry Formulas for Structure of Atom Part 1

Chemistry Formulas of Structure of Atom

Chemistry Formulas from Rutherford Atomic Model

·         Radius of Nucleus, rn = r0 × A1/3
Where, A = Mass Number,
               r0 = Proportionality Constant = 1.4 × 10-13 cm
·         Volume of the nucleus = Approx. 10-39 cm3
·         Volume of the atom = Approx. 10-24 cm3
·         Density of the nucleus = 1014 g cm-3
Or,

Important Characteristics of Three Fundamental Particles
1.      Electron
·         Charge on an Electron = -1.602×10-19 coulombs.
·         Mass of an Electron = 9.11×10-28 g
·         Specific Charge (e/m ratio) of electrons (cathode rays) = 1.76×108 coulombs/gram
·         Radius of the electron = 10-15 cm
·         Density of the electron = 2.17×1017g/cc
·         Mass of one mole of the electrons = Approx. 0.55mg
·         Charge on one mole of the electrons = 96500 Coulombs = 1 Faraday
2.      Proton
·         Mass of Proton = 1.672×10-24g
·         Charge on Proton = 1.602×10-19 Coulombs
·         Specific Charge of Proton = 9.58×104 Coulombs/gram
·         Mass of one mole of proton = 1.007 gram
·         Charge on one mole of proton = 96500 Coulombs = 1 Faraday
·         Volume of Proton = Approx. 1.5×10-38cm3
3.      Neutron
·         Mass of Neutron = 1.675×10-24g
·         Specific Charge on Neutron = 0
·         Density of Neutron = 1.5×1014g/cc
·         Mass of one mole of neutron = 1.008g
4.      Other Sub-Atomic Particles of Atom
·         Positrons
·         Neutrions
·         Mesons
Chemistry Formulas of Atomic Number (Z) and Mass Number (A)
·         General Symbol for an Atom of Element (E) indicating its Atomic Number (Z) and Mass Number (A)
ZEA
·         Atomic Number (Z) = Number of Protons = Number of Electrons
·         Mass Number (A) = Number of Protons + Number of Neutrons
·         No. of Neutrons = A – Z

Sunday, 7 May 2017

Chemistry formulas for Atoms, Molecules and Chemical Arithmetic Part II

Chemistry formulas for Atoms, Molecules and Chemical Arithmetic Part II

Gram Atomic Weight (GAW) related Chemical Formulas

·         No. of Gram Atoms or Mole Atoms = Weight of an Element/GAW
·         Weight of an Element in gram = No. of Gram Atoms x GAW
·         No. of atoms in 1 GAW = 6.02x1023
·         No. of atoms in given substance = 6.02x1023 x Weight/GAW
·         No. of atoms in 1 gram of an element = 6.02x1023/Atomic Weight

Gram Molecular Weight (GMW) related Chemical Formulas

·         No. of Gram molecules or Mole Molecules = Weight of Substance/GMW
·         Weight of Substance in gram = No. of Gram Molecules x GMW
·         Avogadro’s No. = 6.02x1023 per mol

Mole Concept related Chemical Formulas

·         1 mole contains 6.02x1023 particles
·         1 mole of an atom = 1 GAW of it
·         1 mole of a compound = 1 GMW of it
·         Examples, 1 mole of Na = 23 g
·         1 mole of H2O = 18 g
·         1 mole of OH- ions = 17 g
·         1 mole = 1 gram molecules
·         1 mole = 1 gram molecular weight
·         1 mole = 22.4 litres at NTP
·         1 mole = 6.02x1023 molecules
·         1 mole = 1 gram atomic weight
·         1 mole = 6.02x1023 atoms
·         No. of Moles = Weight of Substance in Gram/Gram Molecular Weight
·         No. of Moles = No. of Unitary Particles/Avogadro’s No.
·         No. of Moles = Volume in Litres at NTP/22.4 Litres

Gram Molecular Volume related Chemical Formulas

·         1 Gram Molar Volume = 22.4 Litres
·         Example, Volume of 16 gram (1 mole) of CH4 at STP= 22.4 Litres
·         Volume of 2 gram (1 mole) of H2 at STP = 22.4 Litres
·         Weight of 11.2 litres of any Gas at STP = VD (Vapour Density) of that Gas in Gram
·         Density of Gas at NTP = Molar Weight in Gram/22400 mL

Chemistry formulas





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Saturday, 6 May 2017

Chemistry formulas for Atoms, Molecules and Chemical Arithmetic Part I

Chemistry formulas for Atoms, Molecules and Chemical Arithmetic Part I

Atomic Weight related Chemical Formulas

·         Atomic Weight of an Element = Weight of an average Atom of that Element/ (1/12)x Mass of an element of C12
·         1 a.m.u. = 1.66x10-24g
·         Atomic Weight = Gram Atomic Weight (GAW)
·          1 Gram Atomic Weight (GAW) of every element contains 6.023x1023 atoms of that element.
·         No. of gram of an element = weight of element in gram/ Gram Atomic Weight (GAW) of that element

Methods of Determining Atomic Weight

                         i.     Dulong and Pettits Method: 

                                                                  Applicable only for solid elements except Be, B, C, Si.
·      Atomic Weight  x Specific Heat = 6.4 (app.)
·      Atomic Weight  (app.) = 6.4/ Specific Heat (in Calories)
·      Exact Atomic Weight = Equivalent Weight x Valency
·      Valency = App. Atomic Weight / Equivalent Weight

                        ii.     Vapour Density Method: 

                                                              Applicable only for those elements whose chlorides are volatile.
·         Valency of the Element = Molecular Weight of Chloride / Equivalent Weight of Chloride
·         Valency of the Element = (2 x V.D. of Chloride) / (Equivalent Weight of Metal + 35.5)
Where, V.D. = Vapour Density
·         Atomic Weight = Equivalent Weight of Metal x Valency

                      iii.     Specific Heat Method: 

                                                          Applicable only for Gases.
·         Cp/Cv for monoatomic gases = 1.66
·         Cp/Cv for diatomic gases = 1.40
·         Cp/Cv for triatomic gases = 1.33
·         Atomic Weight of Gaseous Element = Molecular Weight/ Atomicity
Where, Atomicity is number of atoms present in a molecule of a gaseous element. For example atomicity of Inert Gas is 1, atomicity of Ozone is 3, atomicity of H2 N2 O2 X2 is 2, and atomicity of Sulphur is 8.

                     iv.     Volatile Chloride Formation Method:

·         Atomic Weight of the Element = Equivalent Weight (Z) x Valency (x)

                       v.     Isomorphism Method: 

                                                        This method based on law of Isomorphism. According to law of Isomorphism, “Compounds having identical crystal structure have similar constitution and chemical formula”
·         Atomic Weight = Equivalent Weight x Valency
·         Weight of Element A that combines with certain weight of other elements/Weight of Element B that combines with the same weight of other elements = Atomic Weight of A / Atomic Weight of B

Molecular Weight related Chemical Formulas

·         Molecular Weight = Weight of 1 Molecule of the Substance/ (1/12)x Weight of 1 atom of C12
·         Actual Weight of 1 Molecule = Molecular Weight x 1.66x10-24g

Methods of Determining Atomic Weight

1.              Diffusion Method: 

                                          Applicable only for gases.
 ·         


Where,  r1 & r2 is rate of diffusion of gases and M1 & M2 is Molecular Weight.

2.              Vapour Density Method: 

                                                    Applicable only for gases.
·         Molecular Weight = 2 x Vapour Density

3.              Victor Mayer Method:  

                                                 Applicable only for volatile liquids and solids.
·         Molecular Weight of a substance = 22400 ml of vapour of a substance at STP

Equivalent Weight related Chemical Formulas

·         No. of Gram Equivalent Weight = Weight of the substance in gram/ Gram Equivalent Weight of the substance
·         Equivalent Weight of an Element = Atomic Weight/ Valency
·         Equivalent Weight of an Acid = Molecular Weight/ Basicity
·         Equivalent Weight of an Base = Molecular Weight/ Acidity
·         Equivalent Weight of a Salt = Formula Weight/ Total Positive or Negative Charge
·         Equivalent Weight of a Reducing Agent = Formula Weight/ No. of electrons lost per molecule or Total change in Oxidation Number
·         Equivalent Weight of an Oxidising Agent = Formula Weight/ No. of electrons gained per molecule or Total change in Oxidation Number
·         Equivalent Weight of Radicals = Formula Weight of Radical/ No. of units of Charge

Methods of Determining Equivalent Weight

1.              Hydrogen Displacement Method: 

                                                                   Applicable for metals which can displace or combine with hydrogen.
·         Equivalent Weight of Metal = (Weight of metal x 1.008)/ Weight of Hydrogen Displaced
·         Equivalent Weight of Metal = (Weight of metal x 11200)/ Volume in ml of H2 displaced at STP

2.              Oxide Formation Method:

·         Equivalent Weight of Metal = (Weight of metal x 8)/ Weight of Oxygen
·         Equivalent Weight of Metal = (Weight of metal x 5600)/ Volume in ml of Oxygen at STP

3.              Chloride Formation Method:

·         Equivalent Weight of Metal = (Weight of metal x 35.5)/ Weight of Chlorine
·         Equivalent Weight of Metal = (Weight of metal x 11200)/ Volume in ml of Chlorine at STP

4.              Neutralization Method:

·         Equivalent Weight of Acid or Base = Weight of  acid or base in gram/ (Volume of base or acid in litre required for neutralization x Normality of base or acid)

5.              Metal Displacement Method:

·         Weight of Metal Added W1/ Weight of Metal Displaced W2 = Equivalent Weight of Metal Added E1/ Equivalent Weight of Metal Displaced E2

6.              Electrolytic Method:

·         Gram Equivalent Weight = Electrochemical Equivalent x 96500
·         Weight of X deposited/ Weight of Y deposited = Equivalent Weight of X/ Equivalent Weight of Y

7.              Double Decomposition Method:

·         Weight of Salt taken (W1)/ Weight of ppt. obtained (W2) = Equivalent Weight of Salt (E1)/ Equivalent Weight of Salt in ppt. (E2)

8.              Conversion Method:

·         Weight of Compound A (W1)/ Weight of Compound B (W2) = (Equivalent Weight of Metal + Equivalent Weight of Anion of Compound A)/ (Equivalent Weight of Metal + Equivalent Weight of Anion of Compound B)

9.              Volatile Chloride Method:

·         Equivalent Weight = {(2 x Vapour Density of Chloride)/ Valency} – 35.5

10.          Silver Salt Method: 

                                           Applicable for organic acids
·         Equivalent Weight of Acid = Molecular Weight of Acid/ Basicity


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Wednesday, 3 May 2017

Carbonate Chemical Formula

Carbonate Chemical Formula and Description

Carbonate

It is a salt of the Carbonic Acid characterized by the presence of carbonate ion. Carbonate is a poly-atomic ion with the formula of CO2−
3


Chemical Formula of Carbonate

Carbonate CO2−
3


Structural Formula of Carbonate

Structural Formula of Carbonate

Chemical Properties of Carbonate

Metal carbonates decomposes on heating.

Example of S-Block Carbonates

H2CO3, Li2CO3, Na2CO3

Example of P-Block Carbonates

Al2(CO3)3 , NH4HCO3 , PbCO3

Example of D-Block Carbonates

MnCO3, FeCO3, Ag2CO3 

Saturday, 25 March 2017

Pharmaceutical Chemistry MCQs Part17

Pharmaceutical Chemistry MCQs


Science Quiz by www.ChemistryNotesInfo.com

Pharmaceutical Chemistry MCQ
These are some of the random multiple question answers from Pharmaceutical Chemistry...

1. Sulfonamide metabolism in human body is carried out by:

Oxidation
Conjugation
Methylation
Acetylation


2. H2 gas is produced, when ______ is added to water:

LiH
CH4
NH3
H2S


3. _____ is Anti-hypertensive drug with a Tetrazole ring:

Clonidine
Valsartan
Carbapenams
Captopril


4. ____ blocks H2 receptors:

Mepayramine
Pyrilamine
Diphenhydramine
Cimetidine


5. In which of the following drug the pharmacological activity of the drug is associated with a specific optical isomer:

Aspirin
Adrenaline
Caffeine
Phenobarbitone


6. Oxidation of Galactose with concentrated H2SO4 yields the:

Gluconic Acid
Glucuronic Acid
Mucic Acid
Saccharic Acid


7. _______ functional group is responsible for the instability of the Aspirin:

Ester Functional Group
Alcohol Functional Group
Ketone Functional Group
Ether Functional Group


8. ______ is responsible for the synthesis of prostaglandins in the human body:

Arachidonic Acid
Stearic Acid
Lignoceric Acid
Myristic Acid


9. Chemical shift in the Nuclear magnetic Resonance (NMR) Spectroscopy is expressed by:

mm/mL
Parts Per Million
Ampere
1/cm


10. Which of the following ultraviolet region is used in the drug analysis:

50-200 nm
200-400 nm
400-600 nm
600-800 nm



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Thursday, 16 March 2017

Humidity

What is Humidity?

The simple meaning of humidity is ‘atmospheric moisture’ or ‘amount of water vapor in the atmosphere’.
what is humidity
 Humidity is the amount of water vapors present in the atmosphere (or air). Water vapors are the gaseous state of water and are invisible.
 Humidity can be measured by three ways that are: absolute, relative and specific.
    1.   Absolute humidity is the water content of air in the gram per cubic meter at a given temperature.
     2.   Relative humidity is expressed in percentage, and it measures the current absolute humidity relative to the maximum humidity for that temperature.
    3.   Specific humidity is expressed as the ratio of the mass of the water vapors to the total mass of moist air parcel.

What is Absolute Humidity?

To understand absolute humidity let’s assume you are standing in ground and you collect some air. Now you check that air volume in your chemistry lab and get accurate amount of water vapors in gram. If you collect 1 cubic meter of air volume and it contains 30 gram water vapors than absolute humidity of that ground air is 30 grams per cubic meter. So, now you answer this question i.e. what is absolute humidity.
Absolute humidity (AH) is defined as the total mass (in gram) of water vapor present in a given volume (in cubic meter) of air. Absolute Humidity changes with changes in air temperature and pressure. Absolute humidity is the mass of the water vapors( m H 2 O ) {\displaystyle (m_{H_{2}O})} divided by the volume of the air and water vapor mixture.
AH = m/V
Where, AH = Absolute humidity,
             m = mass of the water vapors( m H 2 O ) {\displaystyle (m_{H_{2}O})},
             V = volume of the air and water vapor mixture.


What is Relative Humidity?

To understand relative humidity let’s assume you are in a building where air absolute humidity is 15 grams per cubic meter at 25 degree Celsius temperature and at 25 degree Celsius temperature highest amount of water vapors is 30 grams per cubic meter (saturated air with water vapors 15 grams per cubic meter). So, now you can calculate relative humidity as follows:
Relative humidity = (15 grams per cubic meter / 30 grams per cubic meter)x100
                            RH = 50%
So, now you answer this question i.e. what is relative humidity.
Relative humidity (RH) is defined as the ratio of the partial pressure of water vapors to the equilibrium vapor pressure of water at a given temperature. If temperature of the atmosphere is lower than relative humidity is higher as cold air (air with low temperature) holds more water vapors (moisture) but, If temperature of the atmosphere is higher than relative humidity is lower as hot air (air with high temperature) holds less water vapors (moisture).

What is Specific Humidity?

To understand specific humidity let’s assume you have an air parcel (air volume or some amount of air) and this parcel contains 10 gram mass of water vapors and total mass of air is 1 kg (including mass of all gases present in air and mass of water vapors) than specific humidity is 10 gram per kilogram. So, now you answer this question i.e. what is specific humidity.
Specific Humidity is defined as the ratio of the mass of water vapors in air to the total mass of the mixture of air and water vapors.
Specific Humidity = mass of water vapor/total mass of air

Difference between Humidity and Relative Humidity

Before going to discuss about “Difference between Humidity and Relative Humidity” we need to understand that what is humidity and what is relative humidity. And to get answer of these two questions just read above paragraph once again if you don’t understand.
Humidity is the amount of water vapors present in the atmosphere (or air). Relative humidity is expressed in percentage, and it measures the current absolute humidity relative to the maximum humidity for that temperature.


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