Which of the following carbon marked with asterisk is expected to have greatest positive charge?

1. *CH3-CH2-Cl 2. *CH3-CH2-Mg+Cl-
3. *CH3-CH2-Br 4. *CH3-CH2-CH3
Hint: consider inductive effect of substituents
 
 Electronegativity of Cl, Br, C and Mg follows the order Cl>Br>C>Mg
*CH3CH2Cl (-I-effect)
*CH3CH2Mg+Cl-
*CH3CH2Br (-I-effect)
*CH3-CH2-CH3 (+I-effect)
-I effect of Cl>Br
Hence, CH3-CH2-Cl has the greatest positive charge.