IMF - Properties of Liquids

PS1.3 - IMF's

Exploring Properties of Water Intro Lab

Properties of Water Lab - Collins2025

Conversation 1: Importance of Intermolecular Bonds

Row numbers are provided so you can refer to specific sections more easily.

Khalid: Hey Fatima, Ayah, did you guys really get what Mr. Collins was saying about intermolecular bonds? I was kind of daydreaming about the last F1 race at Yas Marina Circuit, and all those amazing cars flying around the track. I understand these bonds hold molecules together, but I'm not sure I get why they're so important. Especially here in Abu Dhabi, does it really matter?
Fatima: I think it's more than just holding molecules together, Khalid. Remember how Mr. Collins explained that they determine a substance's state of matter? Like, even in the scorching heat of the Empty Quarter, water in a canteen stays liquid because of its hydrogen bonds. But something like the propane in those camping stoves, it's a gas because its intermolecular forces are much weaker.
Ayah: Oh yeah, that makes sense! And it's not just about whether something is a solid, liquid, or gas. Intermolecular forces also affect things like viscosity. Think about how date syrup is thick and slow to pour, but water flows easily. That's because of the differences in their intermolecular forces.
Khalid: So, stronger intermolecular forces mean a substance is more likely to be a solid or a liquid at room temperature, and it'll be more viscous? What about here in Abu Dhabi, with the heat? Does it make a difference when I'm shopping for the latest phone at Yas Mall?
Fatima: Exactly! And that's why water is so important for life in the desert. Its strong hydrogen bonds give it a high boiling point, so it stays liquid over a wide range of temperatures, even in the midday sun. Plus, its high surface tension allows for capillary action, which helps those date palms draw water up from their roots.
Ayah: And don't forget about how water dissolves so many substances. Mr. Collins said that's because the polar water molecules can interact with the ions in salts and other polar molecules. That's how nutrients are transported in our bodies and how we can make solutions like karak chai to enjoy on a cool evening after a day out at Galleria Mall!
Khalid: Wow, I never thought about it that way. So, these tiny forces are actually responsible for some pretty big things! Things that are really important for life here in Abu Dhabi.
Fatima: They really are! They're like the hidden architects of our world, shaping everything from the majestic Sheikh Zayed Grand Mosque to the intricate patterns on a falcon's feathers.
Ayah: I wonder if we could learn more about how these forces work in different materials around us. Maybe we could even design some experiments to test their strength.
Khalid: That's a great idea! Let's ask Mr. Collins tomorrow if we can use the lab to investigate.

You should be able to answer the following:

Explain why water stays liquid at room temperature in Abu Dhabi, while propane in a camping stove is a gas.
Why is date syrup more viscous than water? How do intermolecular forces explain this difference?
How do the strong hydrogen bonds in water contribute to the survival of date palms in the Abu Dhabi desert?
Why is water able to dissolve many substances, like the ingredients in karak chai? How do its intermolecular forces allow this to happen?
Khalid mentions the F1 cars at Yas Marina Circuit. How do intermolecular forces play a role in the tires gripping the track and the brakes slowing down the cars?

Viscosity / Surface Tension Experimentation

Surface Tension and Viscosity lab (2022) - Online

CER Creation Description is HERE

Viscosity Model Data

Make a COPY HERE

Properties Affected by Intermolecular Forces:

Viscosity - How liquids flow
Solubility - How much will dissolve?
Adhesion/Cohesion - Sticking together or to others.
Surface Tension - How much will it support?
Vapor Pressure - What are the limits to evaporation?
Melting Point - At what temperature does a solid turn to liquid (and v.v.).
Boiling Point - At what temperature does a liquid turn to gas (and v.v.).
Evaporation - Changing states without passing the boiling point.

HS-PS 1.3 -

Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces (IMFs) between particles.

Viscosity - See Data Above

Viscosity is a measure of a liquid's resistance to flowing. Thin, low viscosity liquids flow easily. Thick high viscosity liquids flow more slowly or require the shear stress application to induce flow. Eventually all solids will flow in response to shear stress, so solids can, in principle, be considered as liquids with a very high viscosity.

Diamond - viscous liquid or solid?

Resources:

Possible Equipment:

Viscosity Tubes
Flow Rate Monitor
Ramps

The Tenth Watch for the ninth Pitch Drop.In 86 years, no one has seen a drop fall from the longest running lab experiment. But now’s your chance to add your name to the history books.

ViscosityIf you poured some water down a slope, it would flow freely and quickly, but what about if you repeated the process with honey? Can you imagine how honey would flow down a slope? Sticky oozy honey would probably move quite a bit slower than the water. This is because honey has a different viscosity to water.

Solubility

Pill gel-capsule dissolving in water,

Imagine adding a small amount of sugar to a glass of water, stirring until all the sugar has dissolved, and then adding a bit more. You can repeat this process until the sugar concentration of the solution reaches its natural limit, a limit determined primarily by the relative strengths of the solute-solute, solute-solvent, and solvent-solvent attractive forces.

M&M dissolving in water

General Resources:

Solubility Terms:

Solvent
Solute
Concentration
Likes dissolve Likes

Making Hard Candy

Cohesion - Adhesion - Capillary Action

The root word is -hesion, compare the prefixes of co- and ad-.

Predict how the powder the water drops are rolled in affects the cohesion of the water.

Cohesion refers to the attraction of molecules for other molecules of the same kind, and water molecules have strong cohesive forces thanks to their ability to form hydrogen bonds with one another.

Adhesion is the attraction of molecules of one kind for molecules of a different kind, and it can be quite strong for water, especially with other molecules bearing positive or negative charges.

The GIF above represents 3 tubes of different diameter made of the same material. Describe the relationship between the diameter of the tube and the height the water reaches.

The gif above shows building towers with sand. How the amount of water in the sand determine the ability to stack the sand?

Surface Tension

Water striders can walk on water by exploiting water's high surface tension.

Bubbles are spheres due to the high surface tension of water.

The molecules at the surface of a glass of water do not have other water molecules on all sides of them and consequently they cohere more strongly to those directly associated with them (in this case, next to and below them, but not above) - USGS Surface Tension and Water

Measuring Surface Tension: Some Methods

Boiling Point

A liquid boils at a temperature at which its vapor pressure is equal to the pressure of the gas above it. The lower the pressure of a gas above a liquid, the lower the temperature at which the liquid will boil.

2.11: Intermolecular Forces & Relative Boiling Points (bp)The relative strength of the intermolecular forces (IMFs) can be used to predict the relative boiling points of pure substances.

Evaporation

Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.[1] The surrounding gas must not be saturated with the evaporating substance.

Sports Science A better way to Evaporate

Evaporative Salt Mining

If sweat is salty does it cool the skin faster?

Vapor Pressure

Vapor Pressure is closely tied to Evaporation and Volatility.

Vapor pressure is a property of a liquid based on the strength of its intermolecular forces. A liquid with weak intermolecular forces evaporates more easily and has a high vapor pressure. A liquid with stronger intermolecular forces does not evaporate easily and thus has a lower vapor pressure.

Vapor Pressure: A measure of the force exerted by a gas above a liquid in a sealed container.

Melting Point - Data from Bonding Patterns

Melting point, temperature at which the solid and liquid forms of a pure substance can exist in equilibrium. The temperature of the solid/liquid remains constant during this phase change.

Resources:

Predicting Melting Points

Factors affecting Melting and Boiling Points:

Pressure (Change the environment)
Molecular Weight (change the substance)
Structure of Molecule (change the substance)
- Branching
- Polarity
- IMF - Hydrogen Bonding, Dispersion Forces
Impurities
- Changes in concentration of solute (salt, sugar, soap, vinegar, oil)

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