Почему молекулы алканов в пространстве имеют зигзагообразную форму

Alkanes (also saturated hydrocarbons , paraffins ) are acyclic hydrocarbons of a linear or branched structure, containing only simple bonds and forming a homological series with the general formula C n H 2n + 2 .

Explanation:

ll alkanes belong to a larger class of aliphatic hydrocarbons. Alkanes are saturated hydrocarbons, that is, they contain the maximum possible number of hydrogen atoms for a given number of carbon atoms. Each carbon atom in the alkane molecules is in a state of sp 3 - hybridization  - all 4 hybrid orbitals of the C atom are identical in shape and energy, 4 bonds are directed to the vertices of the tetrahedron at angles of 109 ° 28 '. C – C bonds are σ bonds characterized by low polarity and polarizability . The C – C bond length is 0.154 nm , the C – H bond length is 0.1087 nm.

The simplest member of the class is methane (CH 4 ). The hydrocarbon with the longest chain — noncontactrictan C 390 H 782 — was synthesized in 1985 by English chemists I. Bidd and MK K. Whiting

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"