H2 has what kind of intermolecular forces

Correct answer: Ammonia. Example Question 3 : Intermolecular Forces. Order the following compounds from lowest boiling point to highest: He 2 helium gas Isobutyl alcohol Acetone Water. Possible Answers: Helium gas, acetone, water, isobutyl alcohol. Correct answer: Helium gas, acetone, water, isobutyl alcohol. Explanation : Helium gas will have the lowest boiling point since it is a noble gas and the only intermolecular forces present are dispersion forces, which are the weakest.

Example Question 4 : Intermolecular Forces. Put the following in order from greatest to least intermolecular forces: I. Example Question 5 : Intermolecular Forces. Put the following intermolecular forces in order of decreasing strength: London dispersion forces; hydrogen bonds; dipole-dipole interactions; ion-dipole interactions. Possible Answers: ion-dipole interactions hydrogen bonds dipole-dipole interactions London dispersion forces. Hydrogen bonds ion-dipole interactions dipole-dipole interactions London dispersion forces.

Hydrogen bonds dipole-dipole interactions London dispersion forces Ion-dipole interactions. Dipole-dipole interactions Hydrogen bonds Ion-dipole interactions London dispersion forces. Correct answer: ion-dipole interactions hydrogen bonds dipole-dipole interactions London dispersion forces.

Explanation : Ion-dipole forces are the forces responsible for the solvation of ionic compounds in aqueous solutions, and are the strongest of the intermolecular foces. Example Question 6 : Intermolecular Forces.

Which of the following intermolecular forces account for the fact that noble gases can liquefy? Possible Answers: Ion dipole interactions. Correct answer: Dispersion forces. Explanation : Noble gases are uncharged and do not have polar covalent bonds or dipole moments. Which of the following is most similar to hydrogen bonding? Possible Answers: Two methane molecules are attracted to one another because of temporary dipoles.

Correct answer: The slightly negatively charged sulfur atoms in are attracted to the slightly positively charged hydrogen atom of a nearby molecule. Explanation : The choice "The slightly negatively charged sulfur atoms in are attracted to the slightly positively charged hydrogen atom of a nearby molecule" is exactly analogous to hydrogen bonding in water.

Example Question 8 : Intermolecular Forces. Possible Answers: Dipole-dipole interactions. Correct answer: Ionic bonding. Explanation : Methanol is not an ionic molecule and will not exhibit intermolecular ionic bonding. Example Question 9 : Intermolecular Forces. Which of the following intermolecular forces creates the strongest relative attraction? Possible Answers: Hydrogen bonding. Correct answer: Dipole-ion interactions. Explanation : Dipole-ion interactions an attraction between an ion and a neutral, but polar atom are the strongest intermolecular forces listed.

Example Question 10 : Intermolecular Forces. Which intermolecular force is responsible for the high surface tension of water? Possible Answers: Van der Waals forces. Correct answer: Hydrogen bonding. Explanation : Hydrogen bonding is what holds the hydrogen in one molecule of water to the oxygen in another molecule.

When this occurs, non-polar molecules form weak attractions with other non-polar molecules. These London dispersion forces are often found in the halogens e.

London dispersion forces are part of the van der Waals forces, or weak intermolecular attractions. Interactive: Charged and Neural Atoms : There are two kinds of attractive forces shown in this model: Coulomb forces the attraction between ions and Van der Waals forces an additional attractive force between all atoms.

What kinds of patterns tend to form with charged and neutral atoms? How does changing the Van der Waals attraction or charging the atoms affect the melting and boiling point of the substance? Interactive: Comparing Dipole-Dipole to London Dispersion : Investigate the difference in the attractive force between polar and non-polar molecules. Interactive: Factors Affecting London Dispersion Attractions : Explore the role of size and shape in the strength of London dispersion attractions.

Van der Waals forces help explain how nitrogen can be liquefied. Nitrogen gas N 2 is diatomic and non-polar because both nitrogen atoms have the same degree of electronegativity. If there are no dipoles, what would make the nitrogen atoms stick together to form a liquid?

London dispersion forces allow otherwise non-polar molecules to have attractive forces. However, they are by far the weakest forces that hold molecules together. Liquid nitrogen : Without London dispersion forces, diatomic nitrogen would not remain liquid. Privacy Policy. Skip to main content. Liquids and Solids. Search for:. Intermolecular Forces Dipole-Dipole Force Dipole-dipole interactions are intermolecular attractions that result from two permanent dipoles interacting.

Learning Objectives Explain the cause of a dipole-dipole force. Key Takeaways Key Points Dipole -dipole interactions occur when the partial charges formed within one molecule are attracted to an opposite partial charge in a nearby molecule. Polar molecules align so that the positive end of one molecule interacts with the negative end of another molecule.

Unlike covalent bonds between atoms within a molecule intramolecular bonding , dipole-dipole interactions create attractions between molecules of a substance intermolecular attractions. Key Terms hydrogen bond : An intermolecular attraction between a partially positively charged hydrogen in one molecule and a partially negatively charged oxygen, nitrogen, or fluorine in a nearby molecule.

Dipoles generally occur between two nonmetals that share electrons as part of their bond. Factors that contribute to this include intramolecular dipoles and molecular geometry. Hydrogen Bonding A hydrogen bond is a strong intermolecular force created by the relative positivity of hydrogen atoms. Learning Objectives Describe the properties of hydrogen bonding.

Key Takeaways Key Points Hydrogen bonds are strong intermolecular forces created when a hydrogen atom bonded to an electronegative atom approaches a nearby electronegative atom.

Greater electronegativity of the hydrogen bond acceptor will lead to an increase in hydrogen-bond strength. The hydrogen bond is one of the strongest intermolecular attractions, but weaker than a covalent or an ionic bond.

Hydrogen bonds are responsible for holding together DNA, proteins, and other macromolecules. Key Terms electronegativity : The tendency of an atom or molecule to draw electrons towards itself, form dipoles, and thus form bonds. Ion-Dipole Force The ion-dipole force is an intermolecular attraction between an ion and a polar molecule. Learning Objectives Define ion-dipole force.

Key Takeaways Key Points An ion — dipole interaction occurs between a fully charged ion and a partially charged dipole. The strength of the ion-dipole force is proportionate to ion charge. An ion-induced dipole interaction occurs between a fully charged ion and a temporarily charged dipole. The temporary dipole is induced by the presence of the ion. Key Terms ion : An atom or group of atoms bearing an electrical charge, such as sodium and chlorine in table salt.

If you are interested in the bonding in hydrated positive ions, you could follow this link to co-ordinate dative covalent bonding. The diagram shows the potential hydrogen bonds formed with a chloride ion, Cl-. Although the lone pairs in the chloride ion are at the 3-level and would not normally be active enough to form hydrogen bonds, they are made more attractive by the full negative charge on the chlorine in this case.

However complicated the negative ion, there will always be lone pairs that the hydrogen atoms from the water molecules can hydrogen bond to. An alcohol is an organic molecule containing an -OH group. Any molecule which has a hydrogen atom attached directly to an oxygen or a nitrogen is capable of hydrogen bonding. Hydrogen bonds also occur when hydrogen is bonded to fluorine, but the HF group does not appear in other molecules.

Molecules with hydrogen bonds will always have higher boiling points than similarly sized molecules which don't have an an -O-H or an -N-H group. The hydrogen bonding makes the molecules "stickier," such that more heat energy is required to separate them. This phenomenon can be used to analyze boiling point of different molecules, defined as the temperate at which a phase change from liquid to gas occurs.

They have the same number of electrons, and a similar length. The van der Waals attractions both dispersion forces and dipole-dipole attractions in each will be similar. However, ethanol has a hydrogen atom attached directly to an oxygen; here the oxygen still has two lone pairs like a water molecule.

Hydrogen bonding can occur between ethanol molecules, although not as effectively as in water. Except in some rather unusual cases, the hydrogen atom has to be attached directly to the very electronegative element for hydrogen bonding to occur. The boiling points of ethanol and methoxymethane show the dramatic effect that the hydrogen bonding has on the stickiness of the ethanol molecules:. It is important to realize that hydrogen bonding exists in addition to van der Waals attractions. For example, all the following molecules contain the same number of electrons, and the first two have similar chain lengths.

The higher boiling point of the butanol is due to the additional hydrogen bonding. Comparing the two alcohols containing -OH groups , both boiling points are high because of the additional hydrogen bonding; however, the values are not the same. The boiling point of the 2-methylpropanol isn't as high as the butanol because the branching in the molecule makes the van der Waals attractions less effective than in the longer butanol.

Hydrogen bonding also occurs in organic molecules containing N-H groups; recall the hydrogen bonds that occur with ammonia. The two strands of the famous double helix in DNA are held together by hydrogen bonds between hydrogen atoms attached to nitrogen on one strand, and lone pairs on another nitrogen or an oxygen on the other one.

In order for a hydrogen bond to occur there must be both a hydrogen donor and an acceptor present. The donor in a hydrogen bond is usually a strongly electronegative atom such as N, O, or F that is covalently bonded to a hydrogen bond. The hydrogen acceptor is an electronegative atom of a neighboring molecule or ion that contains a lone pair that participates in the hydrogen bond.

Since the hydrogen donor N, O, or F is strongly electronegative, it pulls the covalently bonded electron pair closer to its nucleus, and away from the hydrogen atom.

The hydrogen atom is then left with a partial positive charge, creating a dipole-dipole attraction between the hydrogen atom bonded to the donor and the lone electron pair of the acceptor. This results in a hydrogen bond. Although hydrogen bonds are well-known as a type of IMF, these bonds can also occur within a single molecule, between two identical molecules, or between two dissimilar molecules.

Intramolecular hydrogen bonds are those which occur within one single molecule. This occurs when two functional groups of a molecule can form hydrogen bonds with each other. In order for this to happen, both a hydrogen donor a hydrogen acceptor must be present within one molecule, and they must be within close proximity of each other in the molecule.

For example, intramolecular hydrogen bonding occurs in ethylene glycol C 2 H 4 OH 2 between its two hydroxyl groups due to the molecular geometry. Intermolecular hydrogen bonds occur between separate molecules in a substance. They can occur between any number of like or unlike molecules as long as hydrogen donors and acceptors are present in positions where they can interact with one another. When we consider the boiling points of molecules, we usually expect molecules with larger molar masses to have higher normal boiling points than molecules with smaller molar masses.

This, without taking hydrogen bonds into account, is due to greater dispersion forces see Interactions Between Nonpolar Molecules. Larger molecules have more space for electron distribution and thus more possibilities for an instantaneous dipole moment. However, when we consider the table below, we see that this is not always the case. We see that H 2 O, HF, and NH 3 each have higher boiling points than the same compound formed between hydrogen and the next element moving down its respective group, indicating that the former have greater intermolecular forces.