Water and Polarity Flashcards

Questions and Answers

What is the polarity of water?

Both hydrogen atoms are negatively charged

Water has polar covalent bonds (correct)

Oxygen is partially negative and hydrogen is partially positive (correct)

Water is nonpolar

What causes polarity in water?

Electronegativity

What is a covalent bond?

A chemical bond formed when two atoms share electrons.

What does hydrophilic mean?

Water loving Signup and view all the answers

What does hydrophobic mean?

Water fearing Signup and view all the answers

How do water molecules form?

Oxygen and hydrogen form covalent bonds. Signup and view all the answers

Why does water stick to itself?

Hydrogen bonds Signup and view all the answers

What is a hydrogen bond?

Attraction between a slightly positive hydrogen atom and a slightly negative atom. Signup and view all the answers

What is cohesion?

Attraction between molecules of the same substance. Signup and view all the answers

What is surface tension?

The property of a liquid's surface that allows it to resist an external force. Signup and view all the answers

What is adhesion?

An attraction between molecules of different substances. Signup and view all the answers

What is capillary action?

Both cohesion and adhesion; water moving up a stem. Signup and view all the answers

Why is water like a magnet?

Water has polarity, which means it has a need for more electrons. Signup and view all the answers

What is the difference between hydrogen bonds and covalent bonds?

Hydrogen bonds are attractions between charged molecules; covalent bonds involve sharing electrons. Signup and view all the answers

What is the difference between polar covalent and non-polar covalent bonds?

A polar covalent bond shares electrons unequally, while a nonpolar covalent bond shares them equally. Signup and view all the answers

Why does ice float in liquid water?

Ice is less dense than water. Signup and view all the answers

Why do cracks in pavement widen to become potholes in winter?

Water sinks into cracks, freezes, and expands. Signup and view all the answers

Where is the negative charge located on a water molecule?

Oxygen molecule Signup and view all the answers

Why can polar molecules dissolve in polar solvents?

Polar solvents dissolve polar solutes. Signup and view all the answers

What is condensation?

When water changes from a gas to a liquid. Signup and view all the answers

What is sublimation?

When water changes from a solid directly to a gas. Signup and view all the answers

What is deposition?

When water changes from a gas directly to a solid. Signup and view all the answers

Water has a __________, it can absorb a large amount of heat before a change in temperature takes place.

high specific heat Signup and view all the answers

Why is water a more effective coolant than alcohol for the body?

Alcohol has a lower heat of vaporization and evaporates faster than water. Signup and view all the answers

Study Notes

Polarity of Water

Water exhibits polarity due to polar covalent bonds between hydrogen and oxygen, with hydrogen being partially positive and oxygen partially negative.
Electronegativity is the driving force of polarity, measuring the ability of atoms to attract bonding electrons.

Bonding Types

Covalent bonds involve the sharing of electrons between atoms.
Hydrogen bonds are attractions between a positively charged hydrogen atom and a negatively charged atom.
Polar covalent bonds share electrons unequally between atoms, while non-polar covalent bonds share electrons equally.

Molecular Properties

Hydrophilic substances are attracted to water, whereas hydrophobic substances repel water.
Cohesion refers to the attraction between molecules of the same substance, contributing to high surface tension.
Adhesion is the attraction between molecules of different substances, facilitating water's interaction with various materials.

Water Behavior

Capillary action relies on both cohesion and adhesion, allowing water to move against gravity, such as in plant stems.
Water's polarity causes it to act like a magnet, with hydrogen molecules attracting to negatively charged regions of other molecules.

Ice and Density

Ice floats on water due to its lower density compared to liquid water. Water is unique in that its solid form is less dense than its liquid form.

Seasonal Changes and Effects

Water expands upon freezing, leading to the widening of cracks in pavement during winter as water seeps into them.

Solubility

Polar solvents dissolve polar solutes, highlighting the principle "like dissolves like" in chemistry.

Phase Changes

Condensation is when water changes from gas to liquid.
Sublimation is the transition from solid directly to gas.
Deposition refers to water changing from gas directly to solid.

Heat Properties

Water has a high specific heat, allowing it to absorb significant amounts of heat before temperature changes occur.
Water is a more effective coolant than alcohol due to its higher heat of vaporization, enabling the body to maintain lower temperatures.

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Description

This quiz covers essential concepts related to the polarity of water, including definitions of polar covalent bonds and hydrophilic substances. Understand how electronegativity contributes to water's unique properties. Perfect for students studying chemistry or environmental science!