Question

A monolayer containing 3.19 × 10 –6 g of oleic acid has an area of 20.0 cm 2. The density of oleic acid is 0.895 g / mL. What is the thickness of the monolayer (the length of an oleic acid molecule)?

Answer 1

To find the thickness of an oleic acid monolayer, the mass is first converted to volume using density, and then divided by the area to get the thickness, which is about 1.782 nm in this case.

Step-by-step explanation:

To calculate the thickness of the monolayer of oleic acid, we'll first convert the mass of oleic acid to volume using its density, and then divide that volume by the area to find the thickness.

The density of oleic acid is given as 0.895 g/mL. Thus, for 3.19 × 10−6 g of oleic acid, the volume (V) can be calculated using the formula V = mass/density.

V = (3.19 × 10−6 g) / (0.895 g/mL) = 3.56424581005587 × 10−6 mL

To find the thickness (t), we divide the volume of the monolayer by its area: t = V / Area.

t = (3.56424581005587 × 10−6 mL) / (20.0 cm2)

t = 1.78212290502793 × 10−7 cm or approximately 1.782 nm.

Therefore, the thickness of the oleic acid monolayer is roughly 1.782 nm, which can be taken as the length of an oleic acid molecule.

Answer 2

1.78 × 10⁻⁷ cm

Step-by-step explanation:

Using,

Density = Mass / Volume

Given:

Area = 20.0 cm²

Density = 0.895 g/mL

Mass = 3.19 × 10⁻⁶ g

Applying in the density formula as:

0.895 g/mL = 3.19 × 10⁻⁶ g / Volume (ml)

Volume = 3.56 × 10⁻⁶ mL

Since, 1 mL = cm³

So, Volume = 3.56 × 10⁻⁶ cm³

Thickness (height) of monolayer = ?

Also, Volume = area x thickness

So,

Thickness = Volume/Area = 3.56 × 10⁻⁶ cm³ / 20.0 cm² = 1.78 × 10⁻⁷ cm