First Exam Paper Pdf Download Gujarat Board GSEB.ORG JANUARY 2024 STD9 TO STD 12

Gujarat secondary and higher secondary education board gandhinagar

Factors Affecting Chemical Shift

1). Number Of Protons ( Hydrogen)

• number of Protons Increase Sheilding Increase Delta Parts Per Million Is Low Up Field Occurs




-CH3 -CH2 -CH
§ppm=0.9 §ppm=1.2 §ppm=1.5

 2). ELECTRO POSITIVE NATURE

➤ shielding due to low electronegativity §ppm is very low and Upfield 


C-CH3 Si-CH3
§ppm=0.9 §ppm=0.0

 3). Inductive Effect ( Eletro Negative Nature

➤ if more electro negative Atom Atteched With Carbon proton are Deshielded §ppm is higher And Down field Occurs


C-CH3 C-O-CH3
§ppm=0.9 §ppm=3-4

 4). Hybridization

Sp2>Sp>Sp3

5).Size of Ring:- number of carbon increase in Ring so §ppm High and Down field 

6). Aromatic proton: §ppm have 7 to 8ppm and down field

7). Acidity: increase with §ppm increase Down field Occurs

OH- (7-8), -CHO(9-10),  COOH (10-11)


8). Unsatiration increases with §ppm increase Down field Occurs

9). Effect of solvent

10). Proton of S-H, N-H, O-H affecting