Introduction to Water: Study with Video Lessons, Practice Problems & Examples

Water (H₂O) is a polar molecule due to its polar covalent bonds, resulting in partial positive charges on hydrogen atoms and a partial negative charge on the oxygen atom. This polarity enables hydrogen bonding, which is crucial for water's emergent properties: cohesion, adhesion, low density of ice, high specific heat, and its role as a universal solvent. These properties are essential for sustaining life on Earth, influencing various biological and ecological processes.

Introduction to Water

In this video, we're going to begin our introduction to water. And so, of course, as you guys already know, water is a very small polar molecule with 2 hydrogen atoms and one oxygen atom. And so, of course, its chemical formula is going to be H₂O. One oxygen and 2 hydrogens. Now recall when we first introduced polar covalent bonds in our previous lesson videos, we showed you that water is an example of a molecule with polar covalent bonds, and this is what makes water a polar molecule. Now because water is a polar molecule, it means that it's going to have partial negative and partial positive charges. And so recall that the oxygen atom of every single water molecule is going to have a partial negative charge, whereas the hydrogen atoms on every water molecule are going to have partial positive charges.

And so the partial negative charge and the partial positive charges on water molecules is what allows for water molecules to form hydrogen bonds. And so hydrogen bonds we know will form between different water molecules. And so if we take a look at the right-hand side of our image over here, notice that we're showing you water's hydrogen bonding. And so you can see that the hydrogen bonds are highlighted here in yellow, and the hydrogen bonds are forming between different water molecules. And so this is really really important for many different types of properties that water has and we'll get to talk more about these properties that water has in our next lesson video. So I'll see you guys there.

Individual water molecules bind to each other through:

a) Covalent bonds.

b)   Ionic bonds.

c)   Hydrogen bonds.

d)   Hydrophobic bonds.

• A. Covalent bonds.
• B. Ionic bonds.
• C. Hydrogen bonds.
• D. Hydrophobic bonds.

Introduction to Water

In this video, we're going to briefly introduce some of the emergent properties of water. And so really it's water's hydrogen bonding that gives rise to 4 emergent properties, and really these 4 emergent properties of water are essential to maintain life on Earth. Now moving forward in our course, we're going to talk about each of these 4 emergent properties of water in their own separate videos. But notice down below, we're showing you a table of the 4 emergent properties of water. And so the first is water's ability to perform cohesion, adhesion, and to have surface tension. The second emergent property of water is water's low density when it's in the solid ice form compared to the liquid water form. The third emergent property of water is its high specific heat and heat of vaporization. And then the fourth emergent property of water is that it is used as a universal solvent in mixed solutions. And so once again, we're going to talk about each of these 4 emergent properties of water in their own separate videos moving forward in our course. So I'll see you all in our next video.

Introduction to Water Example 1

Alright. So here we have an example problem that says, which of the following is not an emergent property of water? And we've got these 4 potential answer options down below. Now once again, moving forward in our course, we're going to talk about each of the properties of water in their own separate videos. But from our last lesson video, we should be able to determine what the correct answer is here. And so we know from our last lesson video that one of the properties of water is that it has adhesive and cohesive properties. It can perform cohesion and adhesion. And so because this is definitely something that water is able to do, we can eliminate answer option a since we're looking for options that are not an emergent property of water. And we can also eliminate answer option d since we also know that this is something that water is capable of doing. It is used as the universal solvent in chemical reactions. And so once again, we can eliminate answer option d. So now we're between either option b or option c. And what you might realize is that option c says high density of ice compared to liquid water. Whereas in our last lesson video, we said that there was low density of ice compared to liquid water. And so the high here is actually something that is false because it says high. And so, because this is false, this is not an emergent property of water. This is the one that we're looking for. And so option b must be a property of water, and it says moderation of temperature, and this is something that water is capable of doing. And once again, we'll talk more about this idea later in our course. But for now, we can go ahead and indicate that c here is the one that is not an emergent property of water. And that concludes this example, so I'll see you all in our next video.

The emergent properties of water (cohesion, high heat capacity, good solvent) come from the fact that water is ______ and ______ hydrogen bond.

a) Polar, can.

b) Polar, cannot.

c) Non-polar, can.

d) Non-polar, cannot.

• A. Polar, can.
• B. Polar, cannot.
• C. Non-polar, can.
• D. Non-polar, cannot.

Here’s what students ask on this topic:

What makes water a polar molecule?

Water (H₂O) is a polar molecule due to its polar covalent bonds. In a water molecule, the oxygen atom is more electronegative than the hydrogen atoms, causing the shared electrons to be pulled closer to the oxygen. This results in a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms. The difference in charge distribution creates a dipole moment, making water a polar molecule. This polarity allows water molecules to form hydrogen bonds with each other, which is crucial for many of water's unique properties.

What are the four emergent properties of water that are essential for life?

The four emergent properties of water that are essential for life are: 1) Cohesion, adhesion, and surface tension, which allow water to move through plant vessels and form droplets. 2) Low density of ice compared to liquid water, which ensures that ice floats and insulates aquatic life in cold environments. 3) High specific heat and heat of vaporization, which help regulate temperature in organisms and environments. 4) Water's role as a universal solvent, which allows it to dissolve a wide range of substances, facilitating various biochemical reactions.

How does hydrogen bonding contribute to water's properties?

Hydrogen bonding significantly contributes to water's unique properties. These bonds form between the partial positive charge on hydrogen atoms and the partial negative charge on oxygen atoms of adjacent water molecules. This bonding is responsible for water's high cohesion and adhesion, leading to surface tension. It also contributes to water's high specific heat, allowing it to absorb and release heat with minimal temperature change. Additionally, hydrogen bonding causes ice to have a lower density than liquid water, enabling it to float. These properties are vital for sustaining life on Earth.

Why is water considered a universal solvent?

Water is considered a universal solvent due to its polarity and ability to form hydrogen bonds. The partial positive and negative charges on water molecules allow them to surround and interact with various solutes, effectively dissolving them. This property enables water to dissolve a wide range of substances, including salts, sugars, acids, and gases. As a result, water facilitates numerous biochemical reactions and processes essential for life, such as nutrient transport, waste removal, and chemical signaling within organisms.

What is the significance of water's high specific heat for living organisms?

Water's high specific heat is significant for living organisms because it allows water to absorb and release large amounts of heat with minimal temperature change. This property helps stabilize the internal temperature of organisms, providing a consistent environment for biochemical reactions. It also moderates the climate by buffering temperature fluctuations in the environment. For example, large bodies of water like oceans and lakes can absorb heat during the day and release it at night, maintaining a more stable temperature range, which is crucial for the survival of aquatic and terrestrial life.