See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Analysis of -I Effect (Inductive Effect) The **-I effect** measures how strongly a group withdraws electron density through the sigma bond framework. Stronger electronegativity and more electronegative atoms closer to the attachment point = stronger -I effect. ## Evaluation of Each Group: **$-NO_2$:** Highly electronegative nitrogen with two oxygen atoms pulling electron density. Very strong -I effect. **$-NH_3^{\oplus}$:** Positively charged nitrogen is electron-withdrawing, but less so than $-NO_2$. Moderate -I effect. **$-CN$:** Cyano group has electronegative nitrogen, but the electron withdrawal is distributed along the triple bond. Weakest -I effect among the three. ## Order of Decreasing -I Effect: $$-NO_2 > -NH_3^{\oplus} > -CN$$ (Strongest to weakest) ## Answer: **(3) $-CN > -NO_2 > -\oplus NH_3$** is **INCORRECT** The correct decreasing order should be: **$-NO_2 > -\oplus NH_3 > -CN$** However, if option (3) is marked correct in your source, there may be a notation issue. The standard chemical understanding confirms that $-NO_2$ has the strongest -I effect due to two highly electronegative oxygens directly attached.