Chirality: superimposable or not?किरैलता: अध्यारोपणीय या नहीं?Chirality: superimposable or not?

NCERT Fig 6.5, 6.6 · Class 12 Chemistry · Chapter 6 · interactive diagram

Parts and what they mean

• Propan-2-ol (A) (प्रोपेन-2-ऑल (A)) — Central C carries two identical CH₃ groups — no asymmetric carbon.
• Mirror image of A (B) (A का दर्पण प्रतिबिंब (B)) — Rotating B by 180° gives C, which coincides completely with A.
• Mirror plane (दर्पण तल) — Each structure on the right is the reflection of the one on the left.
• Superimposable → achiral (अध्यारोपणीय → अकिरैल) — Molecules superimposable on their mirror images are achiral and optically inactive.
• Butan-2-ol (D) (ब्यूटेन-2-ऑल (D)) — C-2 has four different groups: OH, H, CH₃, C₂H₅.
• Mirror image of D (E) (D का दर्पण प्रतिबिंब (E)) — However E is rotated (NCERT: F), it never overlaps D.
• Enantiomers (प्रतिबिंबरूप (एनैन्शियोमर)) — Non-superimposable mirror images. Same m.p., b.p., refractive index; they differ only in the direction they rotate plane polarised light.
• Asymmetric carbon (stereocentre) (असममित कार्बन (त्रिविम केंद्र)) — A carbon with four different groups. One such carbon makes the molecule chiral.
• Wedge–dash convention (वेज–डैश परिपाटी) — Solid wedge: bond towards you; hashed wedge: bond going behind the page; plain line: in the plane.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 6.5, 6.6. Report a mistake