Share Answer K-shells contain maximum of 2-electron, L shells can only contain maximum of 8 electrons, M-shells contain
maximum of 18 electrons, N- contains 32 electrons. Calcium with atomic number 20, shows that electrons are added
to a shell until a stable duplet (for the K-shell) and an octet for L-shells. The increase in the number of electron result
in the electrons occupying the shell with next highest energy level so calcium has 2, 8, 8, 2 (A).

Share Answer Synthetic rubber is a polymer and the simple unit (monomer) is 2-methylbuta- 1, 3-diene known as isoprene unit (A).

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MnO^2- = -2
X+(-2x2) =-2
X + -4 = -2
X = +2
MnO4 = -1
X+(-2x4)=-1
X = -1+8
X=+7 (B)

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	C	H
% composition Mole ratio	92.3%	7.7%
	92.3/12	7.7/1
Mole ratio of element	7.67	7.7
Smallest mole ratio	7.67	7.67
=	1	1

Empirical formula = CH (A)

Share Answer Saturated hydrocarbons have single bond around its carbon, so they exhibit SP3 hybridization (A)

Share Answer Electrophiles are electron deficient species like NH4+,H+ (A)

Share Answer The metal must be divalent, i.e. having 2- electrons in its outermost shell to donate to the sulphate, SO₄^2- to give XSO₄ (B)

Share Answer Alkaline pyragallol is used to absorb oxygen (A)

Share Answer CaC₂ + 2H₂O C₂H₂ + Ca(OH)₂
Ethyne (ethylene) produced when passed through oxygen give oxyacetylene flame, used for welding (D)

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M(OH)₃ = 78gmol^-1
M+(16+1)3 = 78
M+(17x3) = 78
M=78-51 = 27(D)