Question

What is the approximate value of the ccc bond angle in
a.ch3ch2ch2oh
b.ch3c≡cch3
c.h2ccch2?

Answer 1

The bond angle varies depending on the type of bond between carbon atoms. For a single bond, its type is the sp³ hybridization. For this type, the bond angle between the carbon atoms is 109.5°. For sp² hybridization (double bonds), the bond angle is 120°. For sp hybridization (triple bonds), the bond angle is 180°. Thus,

A. This is an alcohol which consists of single bonds. So, the angle is 109.5°.
B. The angle is 180° because of the triple bond.
C. H₂C=C=CH₂ consist of a double bond, so the angle is 120°

Answer 2

Answer:

a)109° b)180° c)120°

Explanation:

Hi, in general the bond angle in any molecule depends of:

• The type of bond (single, double, triple)
• The presence of electron pairs the central atom.

In particular for C atoms, there isn't free electron pairs so the angle only depends of the type of bond.

a) Propanol ( $CH_3-CH_2-CH_2-OH$ )

Is this molecule all C have single bonds and an hibridization of sp3, forming a tetrehedral geometry. The bond angle determined for this geometry is arround 109°

b)2-Butyne ( $CH_3-C \equiv C-CH_3$ )

Is this molecule, the triple bond makes a sp hibridization, forming a linear geometry. The bond angle determined for this geometry is 180°

a) Propadiene ( $CH_2=C=CH_2$ )

Because of the double bonds, C have sp2 hibridization, forming a plain geometry. The bond angle determined for this geometry is 120°