Biology Water Study Guide

H2O molecules are ______; they form hydrogen bonds with polar surfaces.

H2O molecules are adhesive; they form hydrogen bonds with polar surfaces.

______ is when water changes from a gas directly to a solid.

Deposition is when water changes from a gas directly to a solid.

Hydroxide Ion

OH-

Hydrogen Ion

H+

Homeostasis

Ability to maintain a steady state despite changing conditions

______ means that water molecules are attracted to other surfaces. This property allows water to spread out on another polar surface. Opposite polar charges attract.

Adhesion means that water molecules are attracted to other surfaces. This property allows water to spread out on another polar surface. Opposite polar charges attract.

______ also allows a student to float a paperclip on the water in a glass because the attraction of water molecules is stronger on the surface of water and below the surface of water than their attraction to the air that is above the water surface. Since the paper clip is so light and has so little of an amount of force in comparison to the strength of the hydrogen bonds, it can float.

Cohesion also allows a student to float a paperclip on the water in a glass because the attraction of water molecules is stronger on the surface of water and below the surface of water than their attraction to the air that is above the water surface. Since the paper clip is so light and has so little of an amount of force in comparison to the strength of the hydrogen bonds, it can float.

______ means that water molecules are attracted to other water molecules. This property allows water to form droplets because the polar water molecules are more attracted to each other than their attraction to a non-polar surface. Opposite polar charges attract.

Cohesion means that water molecules are attracted to other water molecules. This property allows water to form droplets because the polar water molecules are more attracted to each other than their attraction to a non-polar surface. Opposite polar charges attract.

______ is when water changes from a gas to a liquid.

Condensation is when water changes from a gas to a liquid.

Due to water's high ______ ______ capacity, and the fact that the atmosphere is hot, there is a lot more rainfall than snowfall when it precipitates. Droplets in the clouds are also formed to absorb the heat, and when temperature is hotter, there is a greater chance for rain.

Due to water's high specific heat capacity, and the fact that the atmosphere is hot, there is a lot more rainfall than snowfall when it precipitates. Droplets in the clouds are also formed to absorb the heat, and when temperature is hotter, there is a greater chance for rain.

H2O molecules are ______; they form hydrogen bonds with each other.

H2O molecules are cohesive; they form hydrogen bonds with each other.

______ ______ best describes a weak attractive force between water molecules. Since there is enough kinetic energy to break hydrogen bonds, the attraction between water molecules is a weak attraction. These bonds are really just an attraction between a positively charged hydrogen atom and a negatively charged oxygen atom of separate water molecules that are close to each other.

Hydrogen bonding best describes a weak attractive force between water molecules. Since there is enough kinetic energy to break hydrogen bonds, the attraction between water molecules is a weak attraction. These bonds are really just an attraction between a positively charged hydrogen atom and a negatively charged oxygen atom of separate water molecules that are close to each other.

Hydrogen bonds form between adjacent water molecules because the ______ charged hydrogen end of one water molecule attracts the ______ charged oxygen end of another water molecule.

Hydrogen bonds form between adjacent water molecules because the positively charged hydrogen end of one water molecule attracts the negatively charged oxygen end of another water molecule.

Hydrogen bonds form between water molecules. One slightly positively charged hydrogen atom will attract one slightly negatively charged oxygen atom. This attraction, which is weak, can also be formed with other polar molecules, not just water. This is opposed to ______ bonds bonding ions and covalent bonds bonding electrons inside a molecule.

Hydrogen bonds form between water molecules. One slightly positively charged hydrogen atom will attract one slightly negatively charged oxygen atom. This attraction, which is weak, can also be formed with other polar molecules, not just water. This is opposed to ionic bonds bonding ions and covalent bonds bonding electrons inside a molecule.

Why does ice float?

Ice floats because it is less dense as a solid than as a liquid.

Strong ______ have a pH of 1-3

Strong Acids have a pH of 1-3

Strong ______ have a pH of 11 to 14

Strong Bases have a pH of 11 to 14

______ is when water changes from a solid directly to a gas.

Sublimation is when water changes from a solid directly to a gas.

Suspensions

Substances that don't dissolve but separate into tiny pieces.

Sugar and water are similar in the aspect that they both contain ______ atoms. Not only is the electronegativity in both substances very substantial and strong, covalent bonds connect the atoms that make up each substance.

Sugar and water are similar in the aspect that they both contain hydrogen atoms. Not only is the electronegativity in both substances very substantial and strong, covalent bonds connect the atoms that make up each substance.

______ ______ creates the skin-like surface formed due to the polar nature of water.

Surface tension creates the skin-like surface formed due to the polar nature of water.

The electrons are not shared equally, creating a ______ ______ molecule.

The electrons are not shared equally, creating a polar covalent molecule.

The hydrogen and oxygen atoms are held together by ______ bonds.

The hydrogen and oxygen atoms are held together by covalent bonds.

What are the properties of a molecule that would dissociate in water?

The hydrophilic, polar, and ionic properties of a molecule would dissociate in water. The charges aren't shared equally in the polar and ionic properties. The reason why water is polar and not ionic is because of their electronegativity. Water's electronegativity is stronger than ionic substances, which is why they are able to dissociate in water. These two properties of ionic and polar are hydrophilic, so they love water and will be attracted to it.

The polarity of water allows it to ______ most substances. Because of this, it is referred to as the ______ ______.

The polarity of water allows it to dissolve most substances. Because of this, it is referred to as the universal solvent.

This is due to cohesion, because the windshield treatments are made to ______ water (hydrophobic). Since the cohesive water molecules are attracted to each other and not the non-polar surface created by the windshield treatments, the water forms into drops. The drops have less interaction with the surface of the windshield treatment, making it easier to roll off of, as opposed to spreading.

This is due to cohesion, because the windshield treatments are made to repel water (hydrophobic). Since the cohesive water molecules are attracted to each other and not the non-polar surface created by the windshield treatments, the water forms into drops. The drops have less interaction with the surface of the windshield treatment, making it easier to roll off of, as opposed to spreading.

______ is the tendency for fluids to resist flow. ______ water is more viscous than warmer water, allowing floating organisms to use less energy to keep from sinking.

Viscosity is the tendency for fluids to resist flow. Cooler water is more viscous than warmer water, allowing floating organisms to use less energy to keep from sinking.

Water has a ______ heat of vaporization (energy needed to evaporate).

Water has a high heat of vaporization (energy needed to evaporate).

Water has a ______ specific heat.

Water has a high specific heat.

Water is a ______ at normal physiological (or body) temperatures.

Water is a liquid at normal physiological (or body) temperatures.

Water molecules stick to other materials due to its polar nature. This property is called ______.

Water molecules stick to other materials due to its polar nature. This property is called adhesion.

Water molecules stick to other water molecules. This property is called ______.

Water molecules stick to other water molecules. This property is called cohesion.

Water's greatest ______ occurs at 4 Degrees Celsius.

Water's greatest density occurs at 4 Degrees Celsius.

Buffers

Weak acids or bases that react with strong acids or bases to prevent sharp, sudden changes in pH (neutralization).