[MLT-2]

Moles/litre

Three sub shells

James Chadwick

Sodium Aluminium Silicate (Na₂Al₂Si₂O₈.xH₂O) or Zealot.

Acceptor

Negative

RCONH₂

False

True

True

False

False

True

True

Limitations of chemical equation:-
1)    The physical state of reactants and products.
2)    The concentration of reactants and products.
3)    The condition of temperature, pressure, catalyst, etc. which are needed for a reaction.
4)    The state of reaction whether slow or fast.
5)    Time taken by the reaction for completion.

We know the relative atomic mass of 12 C is 124.

So, mass of 1mol C = 12 g

Mass of 6.022 x 10²³C atoms=12 g

Actual mass of 1C atom= 12/6.022 x 10²³ (Avogadro number) = 1.99 x 10^-23 g

Electron:- These are tiny particles which are negatively charged. Electrons revolve in orbital around the nucleus in which protons and neutrons are present. The electrons are negatively charged particles and make the atom neutral because there is equal number of positively charged protons are present in the nucleus. Charge on electron is -1. Mass of electron is 9.11 x 10-31 kg. And represented by  e-.

Proton:- The proton is, in effect, the index particle of any atom. It is the number of protons in an atom that determines the identity of the elements in an atom belongs to. In other words, if two atoms have a different number of protons, they are not the same element. Atoms only exist with only a proton in their nucleus, as is the case with the hydrogen atoms in nucleus protons and nucleus are present. Charge on the proton is +1 and represented by ‘p’. The mass of proton is 1.00728amu (atomic mass unit).

Neutron:- neutron are similar in size of protons, with an amu of 1.00867 and also inhibit the nucleus of atoms. The neutron is a neutral particle. Therefore, the charge on nucleus is zero and represented by n0.

Covalent bonding is chemical bonding process in which pairs of electrons are shared between two atoms. The force of attraction or repulsion between two atoms, when they share electron pair or bonding pairs is called covalent bonding. It occurs between non-metal elements when pairs of electrons are shared by atoms
Example:- simple example is CH4. The carbon atom has 4 electrons in the outer most orbital and for completing its octet and attain nearest noble configuration carbon atom wants 4 electrons. Hence, it makes 4 covalent bond with hydrogen which shares its 4 electrons and makes 4 covalent bonds. 

 The carbon dioxide is also example of covalent bonding (CO2). Here two oxygen gives 4 electrons (one oxygen gives 2 electrons) to the carbon atom.

O : : C : : O

(1) This clarification is based on the atomic number which is more fundamental property of the elements.
(2)  It is easy to remember and reproduce.
(3) The systematic grouping of elements into four blocks s, p, d & f has made the study of the element more simple.
(4) The lanthanides and actinides which have properties different from other groups are placed separately at the bottom of the periodic table.

In boilers, water evaporates continuously and the concentration of the dissolved salts increases progressively. When their concentrations reach saturation point, they are thrown out of water in the form of precipitates on the inner walls of the boiler. If the precipitation takes place in the form of shiny precipitates, it is called “sludge”. On the other hand, if the precipitated matter forms a bond adhering crust/ coating on the inner walls of the boiler, it is called “scale”.

Boyle’s law:- In 1662 Robert Boyle’s law was published according to this law. “The  absolute pressure and volume of given mass confined gas are inversely proportional, provided the temperature remains unchanged within a closed system.”

Mathematically, P₁/V₁ = P₂/V₂   at constant temperature (T).

Avogadro’s law:-  Avogadro’s law state that under condition of constant pressure & temperature. There is a direct relationship between the number of moles and volume of a gas. This law is applicable to ideal gases, while real gases show a slight deviation from it. 
The modern definition of this law is that for particular mass of an ideal gas. The amount (number of moles) and volume of the gas are directly proportional , provided the temperature and pressure conditions are constant.
Mathematically, V/n = k.

Absolute Zero:-  It is defined as the point where no more heat can be removed from a system, according to the absolute or thermodynamic temperature scale. This corresponds to 0 Kelvin or -273.15C. at this temperature at which a thermodynamic system has the lowest energy.

Electrolytes are chemicals that break into ions in water. Aqueous solution containing electrolytes conduct electricity.
Strong Electrolyte:- It includes strong acids, strong base and salts. These chemicals completely dissociate into ions in aqueous solution.
Molecular example:- HCl, HBr, NaOH, NaCl, etc.
Weak Electrolytes:- It only partially breaks into waters. Weak electrolytes include weak acids, weak base & a variety of other compounds. Most compounds that contain nitrogen are weak electrolytes.
For example:- HF, CH₃COOH, NH₃, H₂O (weakly dissociates in itself).

HCl is strong electrolyte & completely dissociate into H⁺ and Cl^-.

pH= -log(H⁺)

so, 0.01M of HCl

H⁺ ions in water =0.01 moles.

pH= -log(0.01)

[log(0.01)=2]

pH=-(-2)

hence, pH=2

Faraday’s Second Law:- This law states that “the mass of a substance deposited or liberated at any electrode on passing a certain amount of charge is directly proportional to its equivalent weight of the substance.
That is, W ∞ E
W is mass of substance in grams.
E is chemical equivalent i.e. weight in grams per equivalent.

Primary Cells:- The cells that can be used only once and disposed after the usage.
Primary cells function with chemical reactions. The discharge rate is lower than that of secondary cells. The initial cost of these cells is lesser than that of secondary cells.
Secondary Cells:- The cells that can be recharged after usage(after discharging), and it is possible to use them several times.
Secondary cells have a quick discharge rate & need to be recharged again and again.
These cells initial cost is more than primary cells. All mobile phones use these kinds of cells.

(a)  Main features of Bohr’s atomic model.
(1)    Electrons revolve in stable orbits around the nucleus. There is no emission of radiant energy. Energy orbit has definite energy called energy shell or energy level.
(2)    An energy level or orbit has been designated as the K,L,M,N shell. An electron is said to be in its ground state when it is in the lowest Energy level.
(3)    While jumping from one orbit or energy level to another, the electron either emits or absorb energy. When the electron jumps from energy shell with higher energy to an energy shell of lower energy, the electron emits energy. But when the electron jumps from the lower energy level to the higher energy level, the electron absorbs energy.
(4)    The energy that is absorbed or emitted by the electron is equal to the difference between the energies of the two energy level (E1 &E2) which is later determined by Plank’s equation

(b) 3Fe + 4H₂O     →      Fe₃O₄+ 8H⁺

(a)  Quantum numbers describe an address or full description of the electrons.
1. Principal quantum number (n):- It defines the main shell to which on electrons belongs. The value of n=1,2,3,4.......
2. Azimuthal quantum number (l):- It tells us the number of sub shells present in the main shell and the orbital to which an electron belongs. Its value to 0 to n-1.
3. Magnetic quantum number(m):- It informs the level of degeneracy of the orbital. Its value is equal to -1,0,+1.
4. Spin quantum numbers (ms):- It tells us that whether the electron is an orbital is spinning in upward direction or downward direction. It has two values +1/2 for upward spin and -1/2 for downward spin.

(b)  Ionic bond is a type of chemical bond that has formed as a result of the complete transfer of valence electrons from one molecule to another metals will transfer their valence electrons to non-metals forming a positively charged ions. The atoms that accept the electrons become negatively charged. The two opposite charge will be attached towards each other and form an ionic bonds and are therefore ionic compounds.

For example:-
Nacl (Sodium Chloride- table salt)
CaCl₂ (Calcium Chloride
NaOH(Sodium Hydroxide- soap)
Fe₂O₃ (Iron Oxide- rust)

(a) Hardness = 

         Hardness  =    = 300ppm    (ppm= 10^1/6)

(b) 1. At normal dilution, value of    is nearly 1 for strong electrolytes, while it is very less than 1 for weak electrolytes.

2. Higher the dielectric constant of a solvent more is its ionising power.

3. α x 1/ concentration of solution x 1/ weight of solution x dilution of solution α x amount of solvent.

4. Degree of ionisation of an electrolyte in solution increases with rise in temperature.

5. Presence of common ion: the degree of ionisation of an electrolyte decreases in the presence of strong electrolytes having a common ion.

(a) Permutit is a man-made zealot. The chemical formula zealot is Na₂AlO₃.nSiO₂.xH₂O.

Zealot is made up of micro-porous minerals which have the capacity of exchanging ions. Hence zealot is used to remove the hardness of water because the zealot contains Sodium(Na) and Aluminium(Al) which makes the water soft in nature.

Ca and Mg is mainly responsible for the hardness of water. A permutit is packed into the reservoir from which the hard water is allowed to pass. When the water passes through permutits; exchange  of ions take place i.e. ca and Mg is replaced by Na and Al.

(b) Oxidation is process in which there is addition of oxygen or removal of hydrogen or removal of hydrogen or removal of electrons from that compound.

For example:-            O      [O]             O

                                 R-C̎-H ---------> R-C̎-OH                          (Addition of oxygen)

                                                   [-2H]            O   

                              R-CH₂OH--------------> R-C̎-H                  (Removal of hydrogen)

                                                        [Ce⁴⁺]

 R-CH₂-O^- -------------> R-CH₂-O              (Removal of electrons)

Reduction is the process in which removal of oxygen or addition of hydrogen or addition of electron from the compound.

                                                                H₂/Catalyst

For example:-  R-CH=CH₂  ---------------------------> R-CH₂-CH₃

(c) The pH scale measures how acidic or basic a substance is. It ranges from 0 – 14. If pH is lower than 7 it indicates the solution is an acid and if it is above 7 then it is a base or alkaline. If pH is 7 then it is neutral. Strong acids have lower pH than the weak acids. Strong bases have higher pH than the weak bases. A pH is measured by dipping litmus into the solution such as water or other substances.

(a)

(b)

Alkane  C_nH_2n+2 ,  Alkene                   C_nH_2n , Alkyne C_nH_2n-2

N = 1,2,3,____

(c) Catenation is the binding of an element to itself through covalent bond to form chain or ring molecules. Carbon is the most common element that exhibits catenation. It can form long hydrocarbon chains and ring like benzene.

-[-CH₂-CH₂-CH₂-]-_n      &