Which statement is true ? (a) The boiling points of diethyl...

Which statement is true ?
(a) The boiling points of diethyl ether and ethyl alcohol are equal
(b) Diethyl ether has dipole moment
(c) Diethyl ether is highly soluble in water
(d) Diethyl ether is a Lewis acid

Key Concepts

Molecular Polarity

This concept explains how the distribution of electrical charge within a molecule creates regions of partial positive and negative charge, giving rise to a net dipole moment. Understanding molecular polarity is crucial in predicting molecular behavior, such as interactions with electric fields and other molecules, which is directly related to the presence of a dipole moment in compounds.

Intermolecular Forces and Boiling Points

Intermolecular forces, including hydrogen bonding, van der Waals forces, and dipole-dipole interactions, play a significant role in determining the physical properties of substances, such as boiling points. Comparing the boiling points of compounds requires an understanding of how these forces differ in strength; for example, molecules capable of hydrogen bonding generally have higher boiling points than those that rely only on weaker dipole-dipole interactions.

Solubility in Water

Solubility in water is largely determined by a compound's ability to form hydrogen bonds with water molecules. Molecules that have functional groups capable of hydrogen bonding or are polar generally have higher solubility in water, while nonpolar or weakly polar substances tend to be less soluble. This concept aids in predicting the miscibility of different compounds with water.

Lewis Acid-Base Theory

This theory categorizes substances based on their ability to donate or accept electron pairs. Lewis acids accept electron pairs, while Lewis bases donate them. Recognizing the acid-base behavior of a compound requires an understanding of its electronic structure and the presence of electron-deficient centers, which is critical for predicting reactivity in various chemical reactions.

Transcript

00:01 This was a strange problem.

00:03 I have a feeling when they put it together.

00:05 They just wanted to make it different from other versions.

00:08 We are given the following information.

00:10 We have two colorless molecular liquids, a and b.

00:14 The boiling points are 78 degrees celsius and 112 degrees celsius.

00:20 Both are at atmospheric pressure.

00:23 We are given five statements and we're asked to determine whether each statement is true or false.

00:30 Correct or not correct.

00:33 Is not correct, we're asked to modify it so that it is correct.

00:38 So i get to write all these out.

00:45 Both a and b are liquids, so that part's true at the conditions we were given, with identical vapor pressures at room temp of 25 degrees celsius.

01:25 And i've got this statement as being incorrect.

01:37 At room temp, liquid a will have greater vapor pressure than liquid b at 25 degrees c and i sort of shorten it up so i didn't have to write so much.

02:09 Statement b liquid a i'm going to abbreviate liq must consist of nonpolar molecules with lower molecular weight than b and this could be true but it doesn't have to be true so this one wasn't like there's so many different things we could modify.

03:14 So i'm just going to put one option here.

03:22 So this part must consist of nonpolar molecules with lower molecular weight.

03:28 Liquid a has weaker intermolecular forces than b.

03:44 It doesn't have to be nonpolar.

03:46 That doesn't necessarily need to be true.

03:48 It doesn't necessarily need a lower molar mass.

03:52 But it does have weaker intermolecular forces.

03:56 Next, c.

04:03 C says both liquids a and b have higher total intermolecular forces than water.

04:31 I should have written this on the last page, imf, than water.

04:38 And this is incorrect.

04:48 Only liquid b...