World Oceans- Chapter 5

Put the phrases in the correct order in which they occur in the oceans to help characterize compensation depth. The top sentence should represent conditions in shallow ocean water. Photosynthetic organism produce oxygen. Carbon dioxide is produce through respiration at the expense of oxygen. Photosynthesis and respiration are balanced at the compensation depth.

1. Photosynthetic organisms produce Oxygen. 2. Photosynthesis and respiration are balanced at the compensation depth. 3. Carbon dioxide is produce through respiration at the expense of oxygen.

About ______ percent of the weight of seawater is dissolved salts.

3.5

What is the average pH of seawater?

7.8

Which of the following correctly describe the pH scale? (Select all that apply.)

A pH above 7 represents an alkaline solution. It is a logarithmic scale It ranged from 0 to 14.

What is a buffer?

A substance that prevents drastic changes in the pH of a solution

Match the way in which salt ions are removed from seawater to its description. Ions bind to clay particles, sink in the water column, and are incorporated into sediments.

Absorption

Match the pH concentration to the correct term. pH less than 7

Acidic

What type of creatures would be found to be living in anoxic conditions in the ocean?

Anaerobic

What is a negatively charged atom or molecule?

Anion

Match the pH concentration to the correct term. pH greater than m7

Basic or alkaline

In which of the following settings would anoxic conditions be likely to occur? Hint: Recall that anoxic means lacking in dissolved oxygen. (Select all that apply.)

Bottom of an ocean trench Isolated, deep basins

How are concentrations of oxygen in seawater measured directly?

By using a probe that sends an electronic signal back to a receiver on a ship or buoy

Ocean acidification primarily is the result of the increase of ______ concentrations in the atmosphere.

CO2

Rank the gases present in the ocean according to their abundance (percent by volume), with the most abundant on top.

Carbon dioxide Nitrogen Oxygen

Describe what happens when carbon dioxide dissolves in seawater by putting the steps below in the correct order, starting with dissolution on top. H2CO3 dissociates into HCO3 (bicarbonate) and H+ or into Co32- (carbonate) and 2H+. Carbon dioxide dissolves in seawater. CO2 combines with H20 to form H2CO3 (carbonic acid).

Carbon dioxide dissolves in seawater. CO2 combines with H20 to form H2CO3 (carbonic acid). H2CO3 dissociates into HCO3 (bicarbonate) and H+ or into Co32- (carbonate) and 2H+.

What is a positively charged atom or molecule?

Cation

Match the way in which salt ions are removed from seawater to its description. Ions react with each other to form insoluble products.

Chemical precipitaion

Rank the major constituents of seawater according to their abundance by weight, with the highest weight at the top and the lowest weight at the bottom.

Chloride Sodium Sulfate Magnesium Calcium Potassium

Match the type of ocean salt to its original source Cations

Earth's crust

The cations found in seawater originally came from ______, whereas the anions originated from ______.

Earth's crust; Earth's mantle

Match the type of ocean salt to its orginal source Anions

Earth's mantle

True or false: Ratios of nutrients such as nitrogen and phosphorus do not vary in seawater.

False

True or false: Water solutions contain only H2O molecules.

False

What is a charged atom or molecule?

Ion

Match the way in which salt ions are removed from seawater to its description. Seawater bodies are cut off, and evaporation leaves behind the salts.

Isolation

What happens to the approximately 300 million metric tons of excess oxygen produced each year by photosynthetic marine organisms? Where does the excess oxygen go?

It is incorporated into sediments and then eventually formed into rocks. It is consumed by bacteriaWater solutions contain ______.

The well-known graph of increasing CO2 concentrations in the atmosphere over the past 50+ years is known as the ______________ curve.

Keeling

Why does ocean salinity change with latitude?

Latitude influences evaporation and precipitation within the hydrologic cycle.

Select the three important nutrients needed for the growth of marine life (i.e., plants, phytoplankton, and diatoms).

Nitrogen Silicate Phosphorus

Carbon dioxide concentrations are low in the ocean's surface waters because it is used in __________.

Photosynthesis

What is the name given to the mean time that a substance remains in the ocean before moving on to another part of the hydrologic cycle?

Residence time

Which of the following are one of the six major constituents of seawater? (Select all that apply.)

Sodium Calcium Potassium Chloride Sulfate Magnesium

Rank the following substances according to pH, with the most acidic on top. Sulfuric Acid Bleach Soda Pop Milk Pure Water

Sulfuric Acid Soda Pop Milk Pure Water Bleach

Which of the following statements correctly describe the Keeling curve? (Select all that apply.)

The data for the curve have been measured at Mauna Loa Observatory, Hawaii. It is a graph of CO2 concentrations in the atmosphere over the past 50+ years.

Although oxygen content generally decreases with increasing depth in the ocean, a noticeable reverse in the trend occurs around 800 meters. Why?

There is a significant drop in the number of animals that are using oxygen.

What happens to the organic substances present in seawater? (Choose all that apply.)

They accumulate in sediments. They are broken down into smaller particles. They are used by organisms.

The equation shown here represents the dissolution of carbon dioxide in seawater. What do the double arrows represent?

They indicate that the reactions can move in either direction.

Which of the phrases does not correctly describe compensation depth? Above this depth, oxygen is added to seawater through photosynthesis and exchange with the atmosphere. Below this depth, carbon dioxide is produced at the expense of oxygen. This depth is permanently at 200 meters below the surface. Carbon dioxide is produced through respiration both above and below this depth.

This depth is permanently at 200 meters below the surface.

What are the two primary current sources for the salts in ocean water?

Volcanism; Runoff from the land

How do changes in CO2 concentration in seawater affect pH?

When CO2 increases, then pH decreases.

You use a salinometer to measure the salinity of two water samples, and the results show that Sample A has a higher conductivity than Sample B. Can you assume that Sample A has a higher salinity?

Yes, because the more ions in the form of dissolved salts available, the more conductive the liquid.

A solution with a pH less than 7 is said to be __________.

acidic

The pH of seawater is slightly ______.

alkaline

The increase in atmospheric CO2 concentrations has resulted in ______ of dissolved CO2concentrations in seawater.

an increase

Photosynthesis in the ocean results in the addition of CO2 into intermediate and deep-ocean water when organisms sink and decay through a process called the __________ pump.

biological

The process by which CO2 (and then carbon) is added to intermediate and deep-ocean water and the ocean bottom, through the involvement of photosynthetic organisms, is called the ______.

biological pump

Match the way in which salt ions are removed from seawater to its description. Animals take in seawater and incorporate the calcium and/or silica into their hard parts.

biological uptake

Water solutions contain ______.

both H2O molecules and H+ and OH- ions

A substance that acts to prevent the sudden change of pH in a solution is called a(n) ____________.

buffer

By measuring the pH of seawater, one can indirectly determine the water's ______ concentration.

carbon dioxide

Increased CO2 concentrations in seawater result in a(n) __________ in pH>

decrease

In general, oxygen content ______ with water depth in the ocean.

decreases

From left to right, this equation describes what happens when carbon dioxide ______________ in seawater.

dissolves

A salinometer measures the salinity of ocean water by measuring ______.

electrical conductivity

Marine plants undergo photosynthesis in the lighted portion of the ocean called the ______ zone.

euphotic

The __________ zone is shallow in coastal waters but may extend to 200 meters in the open ocean where there are fewer suspended particles and sunlight can reach greater depths.

euphotic

Anthropogenic carbon dioxide concentrations in the atmosphere have ______ over the past 150 years.

increased

In general, carbon dioxide content ______ with water depth in the ocean.

increases

A charged atom, group of atoms, or molecules is called a(n) _________. Positively charged examples are called __________ and negatively charged examples are _________.

ion; cation; anion

Ocean salinity changes with ______, as rates of precipitation, evaporation, and runoff are strong influences on how much salt is dissolved in ocean water.

latitude

If seawater becomes too acidic, the reaction moves to the ______, removing free hydrogen ions from the water.

left

Match the pH concentration to the correct term. pH equal to 7

neutral

The most abundant dissolved gases present in the ocean are _________, _________, and carbon dioxide.

nitrogen; oxygen

The ______ present in seawater include proteins, carbohydrates, and fats.

organics

Marine plants undergoing photosynthesis produce and release ______ into seawater.

oxygen

Organisms undergoing respiration remove ______ from seawater and produce and release carbon dioxide.

oxygen

What dissolved gas do heterotrophic organisms take up from seawater in order to respire?

oxygen

The ________ scale represents the acidity or alkalinity of a solution and is based upon the concentration of H+ ions.

pH

Nitrogen, ____________, and silicate are important to different forms of marine life for growth, as they act like the fertilizers of the ocean. These ions are present in very low concentrations in seawater.

phosphorus

Marine plants take up carbon dioxide from seawater in order to ____________.

photosynthesize

Of the liquids listed below, which has the most neutral pH? Milk Ammonia Pure water Orange Juice

pure water

The relative ______ of major seawater constituents remain the same for different geographic locations and water depths.

ratios

The relative ratios of major seawater constituents ______.

remain the same, regardless of depth or geographic location

The average time a substance remains in the ocean (or any specific part of the hydrologic cycle) is called its _________ time.

residence

The ______ of the oceans has remained relatively constant over time because the input of salts is equal to the output.

salinity

The ocean contains an average of 35 parts per thousand dissolved salt; this is the ocean's ______.

salinity

Sea spray that is blown ashore, precipitation in the formation of insoluble deposits on the sea floor, and biological processes are all ways in which _____________ is removed from the ocean.

salt

Volcanism and land runoff provide the _______ now found dissolved in ocean water.

salt

Match the way in which salt ions are removed from seawater to its description. Seawater is blown onto land, taking along and depositing the salts.

sea spray

The concentration of CO2 in the atmosphere has increased over the last 150 years primarily due to ______.

the burning of fossil fuels and deforestation

In order for the salinity of the oceans to have remained the same over the past 1.5 billion years, the input of salts into the ocean needs to equal ______.

the output

The concentrations of nutrient ions in seawater are nonconservative, and they vary because ______.

they are closely related to the life cycles of marine organisms

Match the way in which dissolved constituent concentrations in water are expressed with its scientific unit. Weight Volume Molar Terms

weight- mg/kg volume- mg/l molar terms- moles/kg

Dissolved constituent concentrations in water are expressed in terms of ___________ ,___________ , and molarity.

weight; volume