A1.1.2 Hydrogen bonds as a consequence of the polar covalent bonds within water molecules Flashcards

What causes the polarity of a water molecule?

The polarity of a water molecule is caused by the unequal sharing of electrons between the oxygen and hydrogen atoms, due to oxygen's higher electronegativity.

What is electronegativity?

Electronegativity is an atom's ability to attract electrons in a bond.

What charge does the oxygen atom in a water molecule have?

The oxygen atom develops a partial negative charge (abla−abla−) because it holds the electrons closer.

What charges do the hydrogen atoms in a water molecule have?

The hydrogen atoms develop partial positive charges (abla+abla+) because they lose some of the electron density.

What is the bond angle in a water molecule?

The bond angle in a water molecule is approximately 104.5°.

Define a hydrogen bond.

A hydrogen bond is a weak intermolecular force that forms between a slightly positive hydrogen atom (abla+abla+) in one molecule and a slightly negative atom (abla−abla−) in a neighboring molecule.

Why are hydrogen bonds important?

Hydrogen bonds give water its unique properties, such as a high boiling point, surface tension, and its ability to dissolve many substances.

What is cohesion in terms of water?

Cohesion is the attraction between water molecules due to hydrogen bonding, allowing water to form droplets.

How does water's polarity affect its solvent properties?

Water's polarity allows it to dissolve many substances, which is essential for biological processes like nutrient transport and metabolic reactions.

What is high specific heat capacity?

High specific heat capacity is the amount of energy required to change the temperature of a substance, and water requires large amounts of energy to break hydrogen bonds.

How do hydrogen bonds contribute to water's resistance to temperature changes?

Hydrogen bonds make water resistant to temperature changes because large amounts of energy are required to break these bonds.

What is the difference between a hydrogen bond and a covalent bond?

A hydrogen bond is a weak intermolecular force, while a covalent bond is a strong bond formed by the sharing of electrons.

Give an example of water's unique property due to hydrogen bonding.

Water forms droplets instead of spreading out, due to the cohesive forces of hydrogen bonding between molecules.

What role do hydrogen bonds play in maintaining homeostasis in organisms?

Hydrogen bonds give water a high specific heat capacity, which helps stabilize temperatures and maintain homeostasis in organisms.

Why can insects walk on water?

Insects can walk on water due to the surface tension created by hydrogen bonds between water molecules.