(a) Interpretation: Intrinsic semiconductor: Pure form of semiconductor ( Si, Ge ) is called intrinsic semiconductor it has equal no of hole and free electrons. Extrinsic semiconductor: When very small amount of impurity either trivalent or pentavalent is mixed, obtain extrinsic semiconductor. Concept used: n − type Semiconductor formed by mixing pentavalent atom ( like P ) with pure Si or Ge p − type semiconductor formed by mixing trivalent like Indium ( I n ) , Boron ( B ) , Aluminium ( A l ) etc. with pure Si or Ge . To determine: Indicate if each solid forms a n − type or a p − type semiconductor. (a) Silicon doped with gallium
(a) Interpretation: Intrinsic semiconductor: Pure form of semiconductor ( Si, Ge ) is called intrinsic semiconductor it has equal no of hole and free electrons. Extrinsic semiconductor: When very small amount of impurity either trivalent or pentavalent is mixed, obtain extrinsic semiconductor. Concept used: n − type Semiconductor formed by mixing pentavalent atom ( like P ) with pure Si or Ge p − type semiconductor formed by mixing trivalent like Indium ( I n ) , Boron ( B ) , Aluminium ( A l ) etc. with pure Si or Ge . To determine: Indicate if each solid forms a n − type or a p − type semiconductor. (a) Silicon doped with gallium
Solution Summary: The author explains that intrinsic semiconductor (Si, Ge) has equal no of hole and free electrons. Extrinsic semiconductor: when very small amount of impurity either trivalent or pentavalent is mixed,
Predict the major organic product(s) of the following reactions. Indicate which of the following mechanisms is in operation: SN1, SN2, E1, or E2.
(c)
(4pts)
Mechanism:
heat
(E1)
CH3OH
+
1.5pts each
_E1 _ (1pt)
Br
CH3OH
(d)
(4pts)
Mechanism:
SN1
(1pt)
(e)
(3pts)
1111 I
H
10
Ill!!
H
LDA
THF (solvent)
Mechanism: E2
(1pt)
NC
(f)
Bri!!!!!
CH3
NaCN
(3pts)
acetone
Mechanism: SN2
(1pt)
(SN1)
-OCH3
OCH3
1.5pts each
2pts for either product
1pt if incorrect
stereochemistry
H
Br
(g)
“,、
(3pts)
H
CH3OH
+21
Mechanism:
SN2
(1pt)
H
CH3
2pts
1pt if incorrect
stereochemistry
H
2pts
1pt if incorrect
stereochemistry
A mixture of butyl acrylate and 4'-chloropropiophenone has been taken for proton NMR analysis. Based on this proton NMR, determine the relative percentage of each compound in the mixture