In the fluid-mosaic model that describes cell membranes,
a. there are three layers of glycerophospholipid molecules.
b. two layers of glycerophospholipid molecules have their nonpolar sections oriented to the inside of the membrane.
c. two layers of glycerophospholipid molecules have their nonpolar sections along the outer surface of the membrane.
d. a single row of glycerophospholipid molecules forms a barrier between the inside and outside of the cell.
e. two layers of proteins separate the contents inside a cell from the surrounding fluids.

B. two layers of glycerophospholipid molecules have their nonpolar sections oriented to the inside of the membrane.

Explanation:

Fluid - mosaic model -

The model given by Garth L. Nicolson and S.J. Singer helps to determine the correct composition of the cell membrane .

According to this model , it gives the composition or the structure of the cell membrane or the plasma membrane as a mosaic of components , that are , carbohydrates , proteins , cholesterol , and phospholipids .

The basic framework of this layer , is the molecules of glycerophospholipid , which are dipolar in nature , i.e. polar and nonpolar ends , and hence , are arranged in a manner , to form two layers , where the non polar ends are towards the center and polar are facing outside .

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.