CHEM OF THE HYDROSPHERE

Question 1

[] is defined as the number of dissolved solids per gram of seawater. Studies show that the major ions present in seawater are sodium, potassium, calcium, magnesium and the chloride ion.

Answer 1

Salinity

Question 2

Water molecules is made up of one [] and [] atoms forming two O-H bonds leaving two unpaired electrons on the oxygen. The distribution of forces among the elements results to its bent molecular structure. In addition, the oxygen atoms in the water molecule have high [] which makes them attract the O-H bond creating strong dipoles that attract each other and form new bonds known as the hydrogen bond. The hydrogen bonds among the water molecules are what maintain a strong adhesion among the molecules.

Answer 2

hydrogen
two oxygen
electronegativity

Question 3

[] is not considered as pollutant, but it produces problems at their disposal to
bodies of waters. [] kills some of the water species and it also increase the rate of dissolved oxygen depletion

Answer 3

Heat

Question 4

[] coming from industries may affect the quality of water such that it is no longer
useful for public water supply and irrigation. High salt concentration damages crop and causes soil poisoning.

Answer 4

Salt

Question 5

used when the oxidation process is carried by microorganisms instead of strong oxidizing agent. In a [] test, microorganisms are introduced to a water sample where they oxidize the organic and inorganic
compounds in the dark at 20°C over a period of 5 days.

Answer 5

Biochemical Oxygen Demand (BOD).

Question 6

Apart from evaporation and sublimation, [] also contributes to the amount of water vapor that enters the atmosphere. [] is a
combination of evaporation and transpiration. [] is the process by which plants takes water from the soil through its roots and later released through
its leaves. The water that is released is further evaporated into the air.

Answer 6

evapotranspiration
Transpiration

Question 7

The [] is one of the geological spheres that makes up the earth. It is composed of the different water bodies that are found on the surface and deep below the earth, including the water that is found in the atmosphere.

Answer 7

hydrosphere

Question 8

measures of the amount of the amount of molecular oxygen required to achieve a complete chemical oxidation of a sewage sample using a strong oxidizing agent mixed with a water sample and then heated to 150°C for two hours.

Answer 8

Chemical Oxygen Demand (COD)

Question 9

The presence of [] and [] can be attributed to widespread human activities such as mining ang smelting. These compounds can damage deep-rooted plants and contaminate groundwater. They are in some of their forms are toxic and hazardous both to humans and other organisms. In addition, they also increase the water turbidity and coloration, stain materials in contact to it and gives the water a bad taste.

Answer 9

metallic and metalloid compounds

Question 10

It is a condition when a body of water is enriched with excessive nutrients from surface runoff and stimulates growth of plants. This results to a decrease in the concentration of dissolved oxygen in the body of water causing death to the aquatic species living in it.

Answer 10

eutrophication

Question 11

[] are disease-causing bacteria, viruses and other parasitic organisms that are present in waters usually from untreated sewage. They can contaminate drinking, swimming and bathing waters and food. These media can be used by the [] to access individuals and cause the diseases such as typhoid fever, cholera, diarrhea and dysentery.

Answer 11

Pathogens

Question 12

Evaporation is not the only source of water vapor in air. Some of the water components of ice and snow [] to water vapor. [] is the process wherein the solid water changes into gas.

Answer 12

Sublimation

Question 13

[] and [] are of primary concern
with respect to the water quality because they are essential to the growth of living
organism. Their presence in waters supports the natural food chain; however,
when excessive, some of the organisms proliferate at the expense of others.

Answer 13

phosphorous and nitrogen

Question 14

High COD and BOD values mean [] of the water sample. Discharging water with high COD and BOD values results to a [] of dissolved oxygen in water and may pose threat to the aquatic organisms that require it for respiration.

Answer 14

high organic content
reduction

Question 15

The number of oxygen-demanding compounds present in water can be measured in two (2) ways: [], []

Answer 15

Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD).

Question 16

[] is the process wherein the liquid water changes into gas at ambient temperature. The heating of bodies of water and of lands by the sun causes [] of some of its waters into the air.

Answer 16

Evaporation

Question 17

Mishandled [] are toxic to human health. Most of them came from nuclear facilities and improper disposal of medical applications.

Answer 17

radionuclides

Question 18

[] is formed when the precipitation rate exceeds the infiltration rate.

The excess water flows as runoff and gets to streams, rivers, ponds, lakes, swamps, marshes and springs. The composition of [] depends on the processes that takes place in the geographic zone such as weathering,
precipitation and eutrophication.

Answer 18

Surface water

Question 19

The [] is composed of all waters that are leading to the seas and the oceans
and it comprises [] of the waters in the whole planet Earth.

Answer 19

seawater
97%

Question 20

Natural waters are comprised of [], [], [], [] and []

Answer 20

rainwater, surface water, groundwater, sweater and saline water

Question 21

The clouds are moved by air currents, collide, grow and fall out as []
which is the process wherein liquid or frozen water in the atmosphere goes back
to earth in the form of rain, snow or sleet. Most [] falls back to the land, oceans and other bodies of water.

Answer 21

precipitation

Question 22

Large plastics resemble food of larder organisms in the bodies of water. On the
other hand, [] may be broken down into smaller fragments which may threat the lives of the organisms that happen to ingest them.

Answer 22

plastic debris

Question 23

[] are compounds in water bodies that consume dissolved molecular oxygen. They can either be biodegradable organic or
inorganic compounds. These materials can come from human wastes and food
residues that are dumped into water bodies.

Answer 23

Oxygen-demanding materials

Question 24

When the salt content of the water is greater than the fresh water but lower than
that of the seawater, it is categorized as []. It has an average salt content of 0.5 to 30 g/L. [] are usually classified according to their salinity to check their possibility of being used in irrigation systems. This is because high salt concentration may be toxic to plants or accumulate in plants and later place their consumers at risk.

Answer 24

brackish or saline water

Question 25

The [] involves the physical changes water undergoes as it continuously moves above on and below the surface of the earth. It is also known as the water cycle.

Answer 25

hydrological cycle

Question 26

The water vapor resulting from the processes of evaporation from the oceans,
sublimations from ice and snows and transpiration from plants are carried up into the atmosphere by rising air currents. When the vapor reaches the air of []
temperature, it transforms into [] through the [] which is the process wherein water vapor changes into liquid.

Answer 26

cooler, clouds, CONDENSATION

Question 27

[] is the accumulated water that fills the water table and the aquifers that came from precipitation and was infiltrated through the soil. The [] is below the surface of the ground where water can be found. The [], on the other hand, is made up of permeable rocks that holds a large reservoir of water that can easily be transmitted into springs are wells. [] is also the water in voids and spaces between soil, sand, gravel, clay silt and rocks.

Normally, the groundwater has a pH level of []

Answer 27

Groundwater
water table
aquifers
6.5 to 8

Question 28

[] is the process when water runs over the surface of the earth. The snow precipitates are accumulated as ice caps and glaciers but some of them melts wherein the melted water flows as a snowmelt over lands as []. Some of the precipitation flows over the ground as []. Portions of the runoffs goes to the rivers and oceans. Some of the precipitate go through groundwater seepage and later stored as freshwater in lakes.

Answer 28

Runoff
snowmelt runoff
surface runoff

Question 29

[] spills are products of accidents, lack of maintenance and neglectfulness from machineries. In addition to being displeasing to the eye, [] spills has negative impact on the environment and on the living species in the area because [] are toxic and carcinogenic.

[] emulsions block the entrance of light into the bodies of water resulting in a decrease of biological activities.

Answer 29

Oil and grease
oil

Question 30

comes from the evaporation, condensation and precipitation processes in the water cycle. It takes [] days for the water in the atmosphere before it precipitates as rain. The rainwater composition depends on the zone of the origin of the clouds that carried it, the composition of the winds that carried them to the precipitation cite and on the composition of the atmosphere at the precipitation zone.

Answer 30

rainwater
8 – 10

Question 31

Not all runoffs go back to the hydrosphere, absorbed by plant or get evaporated
because much of the water soaks deep into the soil through the process of []. Some of the water infiltrates deep into the ground to replenish the ground water table and aquifers. Some stays close to the land surface and seeps back into the surface as groundwater discharge and freshwater springs.

Answer 31

infiltration

Question 32

The pH of the rainwater depends on the compounds found in the atmosphere. The
presence of [] makes it slightly acidic. The [] concentration also lowers the pH of rainwater. Compounds such as SO2 and NO2 undergoes oxidation and dissolution to produce sulfuric and nitric acid,
respectively. This is the cause of acid deposition such as acid rain.

Answer 32

carbon dioxide (CO2)
sulfate

Question 33

[] are those that are obtained by evaporating a sample wastewater
to dryness at 103 to 105°C. These TS undergo filtration: the filtered ones are called as [] and those that were dissolved and became part of the filtrate are the []. When the TS are subjected to
ignition at 500°C: the residue is known as the Total Fixed Solids (TFS), while those
that were volatilized are the Total Volatile Solids (TVS).

The higher the content of suspended solids, the more [] the water is

Answer 33

Total solids (TS)
Total Suspended Solids (TSS)
Total Dissolved Solids (TDS)

polluted