Unit 2 Physical Properties of Water-QUESTIONS

Remember the difference between cohesive and adhesive forces.

A good way to remember the difference between adhesive and cohesive forces is that with ADhesive forces you ADD a different set of molecules, to the water the molecules, for the liquid to bond with. With COhesive forces, the molecules of the liquid will only COoperate with their own kind.

What is heat capacity a measure of?

A measure of how much heat a gram of substance must absorb to cause its temperature to rise 1 degree Celsius.

Adhesion

An attraction between molecules of different substances. For instance, adhesion enables water to "climb" upwards through thin glass tubes (called capillary tubes) placed in a beaker of water. This upward motion against gravity, known as capillary action, happens because water molecules are more attracted to the glass tube molecules than to other water molecules.

What influence does water BUOYANCY have on ocean plants/animals?

Animals are denser than either fresh water or sea water, and therefore tend to sink, unless they have adaptations that give buoyancy so they can stay afloat because to prevent them from constantly having to swim and assist with those who do surface feeding.

What is an estuary?

Area where freshwater meets saltwater (where rivers enter into oceans)

How does water's composition lead to surface tension?

At the surface between air and water, water molecules not being pulled by the air above and are only pulled laterally and downwards so this make the hydrogen molecules more densely packed together and stronger at the surface. This stronger, denser arrangement forms a weak elastic membrane which is surface tension.

How does water dissolves other materials?

Because water's polarity it can form spheres around other ions and disrupt the attractive forces that hold them together like with NaCl.

How is the density of a liquid liquid related to viscosity?

Both Viscosity and Density are affected by temperature. When the temperature is increased, its density decreases thus, the fluid becomes less viscous. Reducing ocean viscosity improves ocean circulation and affects climate.

Compare capillary action and adhesion.

Capillary action occurs because water is sticky due to the forces of cohesion (water molecules like to stay close together) and adhesion (water molecules are attracted and stick to other substances). So, Capillary action only occurs when the ADHESIVE forces are stronger than the cohesive forces like water in a capillary tube.

Describe how ocean water is constantly circulating.

Changes in ocean temperature and salinity affect water density which causes cooling and sinking of waters which results in constant ocean water circulation.

How do water molecules lead to cohesion?

Collectively the hydrogen bonds hold water together and this property is called cohesion. An example of cohesion is a water drop composed of water molecules that like to stick together.

What influence does water DENSITY have on ocean plants/animals?

Density is the amount of matter packed into a fixed amount of space and can be affected by pressure, temperature and salinity. Ocean density can impact the climate, marine animals ability to float and even cause fish adaptations to help hunt their prey due to less sunlight in denser water. Some have evolved huge eyes that can see better in the dark such as the giant squid.

Why are fishing nets a problem for coral reefs, marine life and birds?

Fishing nets can result in the entrapment and death of marine mammals, sea birds and fish and can cause coral reef entanglement which breaks the coral and effects the marine life that depend on it.

Contrast freezing points of fresh water and salt water.

Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit , because of the salt in it.

What tidal period does salt water move upstream in estuary?

In an estuary, salt water tends to move upstream during HIGH tide.As the tide rises, water from the ocean begins to surge into the mouth of a river, bringing with it higher levels of salt.

How fast does plastic deteriorate in nature?

Normally, plastic items take up to 1000 years to decompose in landfills.

Why is it difficult to photograph the Great Pacific Gargage Patch?

Ocean debris is continuously mixed by wind and wave action and widely dispersed both over huge surface areas and throughout the top portion of the water. Much of it can be under the surface and not visible in pictures.

Why does viscosity matter to aquatic life?

Ocean viscosity can have an impact on the climate which can affect aquatic life's survival and food chain. Ocean viscosity can specifically impact aquatic life that need a specific viscosity to survive like with suspension feeding.

Real life examples of capillary action:

Paper towels use cohesive and adhesive properties draw the fluid into the paper towel, plants absorbing water from the soil, and tears moving through tear ducts.

How do plastics affect the food chain?

Plastics are a physical hazard to the digestive tracts of fish and can absorb pollutants from the surrounding seawater like. These pollutants, like DDT and and PCB can cause cancer and birth defects. So, plastics can have a negative affect by harming both marine life in the food chain AND possibly humans who eat contaminated aquatic life.

What non-renewable resource is plastic created?

Plastics are made mostly from OIL and NATURAL GAS which are both non-renewable resources. It takes millions of years for the earth to create more crude oil and there's a finite amount of fossil fuels which makes up natural gas. So, manufacturing and using plastics is depleting planet earth's natural resources and they cannot be replaced.

Why do large ships have different Plimsoll marks for salt and fresh water?

Plimsoll mark is a line on side ship that would disappear below the waterline if the ship was overloaded. Because the difference in salinity affecting a ship's buoyancy in salt vs fresh water, the Plimsoll marks are at different levels.

What is the SOFAR channel and what depth does it happen?

SOFAR stands for Sound Fixing and Ranging channel. Sound can travel in a specific ocean layer due to differences in salinity (salt content) and temperature. Saltier and colder water lie beneath less salty, warmer water. Between these layers, sound can be reflected back and forth over large distances. It occurs at depths of approximately 1,000 metres (3,300 feet).

What is SONAR and how does it work?

SONAR is Sound Navigation and Ranging and can be used to tell scientists about the depth and surface of the ocean floor by using a sound that is reflected or backscattered to hydrophone and recorded to detect objects on or under the surface of the water.

What is salinity a measurement of?

Salinity is the measure of the amount of dissolved salts in water.

Why is salt spread on the road during a snowstorm?

Salting roads works by altering the freezing point of water. Water with a higher salt content has a lower freezing point than water with less salinity

How do oceanographers use SONAR to tell what is underwater?

Scientists use scattering, backscattering and absorption are used to determine hard materials like rocks or submarines will scatter and reflect more sound than soft materials like mud or jellyfish. Different amount of scattering produces different amounts of sounds returning to the hydrophone and a different image of the sea floor.

Why is sea ice not as salty as ocean water from which it was formed?

Sea ice is not as salty because when it forms, most of the salt is pushed into the ocean water below the ice. Water below sea ice has a higher concentration of salt and is more dense than surrounding ocean water, and so it sinks. In this way, sea ice contributes to the ocean's global "conveyor-belt" circulation.

Why does sea water conduct electricity, but fresh water does not?

Sea water contains common salt (sodium chloride - ) and other compounds which, when dissolved in water dissociate into ions. These ions are charged particles that can conduct electricity.

What 2 properties of ocean water make it more likely to sink to the ocean floor?

Temperature and Salinity

What is the Great Pacific Garbage Patch?

The Great Pacific Garbage Patch is the largest accumulation of ocean plastic in the world and is located between Hawaii and California which accumulates there due to a large system of swirling ocean currents. This is detrimental for many reasons: 1) Toxic for sea surface feeders 2) Entanglement of marine life 3) Once plastic enters the marine food web, it can contaminate the human food chain 4) Clean up of ocean plastics is huge economic expense

Contrast Glaciers and Icebergs.

The difference between an Iceberg and Glacier is a large mass of snow and ice mixture that covers the valley floor of a mountain range and an iceberg is the piece of a glacier that breaks off of (or calves) when temperatures warm up.

What influence does water VISCOSITY have on ocean plants/animals?

The viscosity (thickness/resistance to motion) of water allows marine creatures like fish to propel themselves using fins. Another example greater viscosity of polar waters allows microorganisms to float more easily than tropic waters.

How do density and buoyancy affect an object's ability to float or sink?

Things float when they are positively buoyant, or less dense than the fluid in which they are sitting. This does not mean that an object has to be lighter than the fluid, as in the case of a boat; objects just need to have a greater ratio of empty space to mass than the fluid.

What is viscosity and what causes it?

Viscosity is the resistance of a fluid to flow or a change in shape and it is due to cohesive forces.

Why is water called the universal solvent?

Water dissolves more substances than any other liquid.

Why is water considered a polar molecule?

Water has positive hydrogen atoms and negatively charged oxygen atoms

What influence does water CAPILLARY ACTION have on ocean plants/animals?

Water uptake involving capillary action is seen in some small animals like sea roaches and can even aid in some ocean creature's movement.

What influence does water SURFACE TENSION have on ocean plants/animals?

Water's surface tension property affects ocean life due the vast variety of marine life that rely on surface tension for its floating existence like certain jelly fishing sea slugs.