VERIFIED CHEMISTRY OBJ
i) Functional group; this is the group of atoms within molecules that are responsible for the xteristic chemical reaction of the molecules
-They react alike
– They have the general formula
this is a structural reprentation of the compounds below but they are in molecular. So try and draw it from it if u can.
iii) 2,2- dimethylpropane
PLEASE USE EMPIRICAL METHOD OF CALCULATION AND SUBSTITUTE THIS VALUES.
%Comp C H O
39.9 6.9 53.3
12 1 16
3.325 6.9 3.331
3.325 3.325 3.325
1 : 2.075 : 1.002
Since ratio must be whole number,then it is
==> Empirical formula is CH2O
Vapour density = 30
Molar mass = Vapour density x 2
=2 X 30 = 60
==> (CH2O)n = 60
(12+2+16)n = 60
30n = 60
n = 60/30=2
Polymerization: this is the combination of many small molecules of a compound to form a giant molecule eg
Synthetic Rubber polythene
Cracking : this is the splitting of large Hydrocarbon molecules into smaller molecules e.g petrol ,kerosine
i)Lactic acid — milk
ii)Ascorbic acid– citrus milk
iii)Amino acid —Soya bean.
Charle’s law stated that the volume of a given mass is directly proportional to its temperature provided that the pressure remains constant.
(Plz note dat & is a directly proportional sign.)
V & T
V/T = K(constant)
a)Atoms are made of electrons,protons and neutrons
b)Atoms are created and destroyed in special changes such as radioactivity.
C)The average mass of an atom of one element is constant, the isotope of an element have the same chemical properties.
Avogadro’s constant ; this is the number of units in one mole of any substance(define its molecular weight in grams)
Equal to 6.02214 x 10^23
V1 = 200cm^3
T1 = 25 + 273 = 298k
P1 = 60,000Nm^-2
T2 = 273K
P2 = 1.01×10^5Nm^-2
V2 = ?
P1VI / T1 = P2V2 / T2
V2 = P1V1T2 / P2T2
V2 = 104.48cm^3.
Iron (ii) Salt.
When potassium heptaoxochromate (vi) is added to a reducing agent; the K2Cr2O7 solution turns from orange to green
i)Hard water forms scum with soap while soft water does not.
ii) Hard water uses more fuel when heating while soft water does not.
Experiment to demonstrate law of conservation of mass.
a) weigh a set of reactant and their container
b) Mix them for the reaction to take place
c) Observe the change showing that new substance is formed.
d) Weigh the product(s) and the same container
There will be no change in masz of the reactant and the product.
a)12c6 :- pick 2
b)13c6 :- 6 protein and 7 neutrins
c)14c6 :- 6 protein and 8 nentrins
ii. Beta radiation
i)It has a mass of 4
ii)It is deflected by electric field
iii)It has low penetrating power.
Nuclear fission: when a nuclear reaction takes place in which a heavy nuclear is split into two or more atoms of similar size eg splitting of uranium238 nuclear.
29v92+1n6-89k36r+144b56a+3 whole no1n0
i)226Ra82-222Ra80+4He2 ii. 210Pb82-210Bi53+0e-1
i)Gieger muller carter
Periodic can stated that when element are arranged an increasing order of their atomic number, there is a periodic repetition of their properties.
a)Electro negativity character halogen has strong tandind to gain one electro to form hydride like wise hydrogen.
b)ionization energy of hydrogen is similar to group VII element.
c)Hydrogen and group VII both has one electron less than the nearest noble gas i.e helium.
i)Ionization energy. This is the energy needed to remove an electron from a gaseous atom.
ii)The ionization energy increases across the period i.e
it increases from left to right on the periodic table.
it show that the ionization energy of group I is less than that of group II element and show on.
iii)Cr48^1 is more stable than Cr t^23dq because two subshell half field are more stable than one subshell half filled and the other subshell not completely filled for 5 electro it is half filled that makes it stable while for S^2 which is completely filled and 3d not filled to half it makes it unstable.
i)n=2 number of electro=2n2=2(2)^2=8
ii)3d number of electro =18
Transition metal, Fe,v,cr,m.
Electronic configuration, 15^225^22p^635^23p6 45^2 3d^6,
i)Why transition metal form column salt: the energy different between 45 and 3d orbital is very small. Electron are thereby easily promoted from 45 to 3d orbital. when such electron return to the ground state the energy different absorbed is remitted and imparting colour to the metal ions.
ii)Why transition metal use as eatalyst: they act as eatalyst because they easily absorb electro into their vacant orbital and gives these up again during reaction.