SC140 Online Exam 4

Question 1 (5 points)

In contrast to going without food, the human body can survive only about __________ days without water.

Question 1 options:

  

3

 

7

 

11

 

15

Question 2 (5 points)

Which of the following sources of water is most likely to contain contaminants?

Question 2 options:

  

Aquifers

 

Distilled water

 

Surface water

 

Groundwater

Question 3 (5 points)

All of the following describe benefits of water acting as a solvent, EXCEPT:

Question 3 options:

  

rainwater carries air pollutants   to earth from the atmosphere.

 

water helps maintain a chemical   balance in our bodies by carrying wastes away.

 

water in blood plasma transports   nutrients to all our ograns.

 

rainwater dissolves   and carries pesticides and fertilizers from farmland to streams and lakes.

Question 4 (5 points)

Given that 1 ppb = 1 microgram/L and that the federal government’s maximum allowable concentration of lead in drinking water is 15 ppb, how many micrograms of lead in 2L of water would meet this standard?

Question 4 options:

  

15

 

30

 

45

 

60

Question 5 (5 points)

How many grams of NACL would you add to 500 mL of water to create a 1.75M solution of NACL? (1M of NACL = 58.5 g)?

Question 5 options:

  

102.38 g

 

58.50 g

 

51.19 g

 

43.88 g

Question 6 (5 points)

Many of the unique properties of water are a consequence of the overall shape of its molecules as well as the:

Question 6 options:

  

polarity of its   bonds within each molecule.

 

small EN difference between oxygen   and hydrogen atoms.

 

equal sharing of electrons between   oxygen and hydrogen atoms.

 

absence of any hydrogen bonds.

Question 7 (5 points)

Ionic compounds are formed when:

Question 7 options:

  

elements from the same side of the   periodic table exchange electrons.

 

metallic elements   and nonmetallic elements exchange electrons.

 

the sum of the negative charges in   both elements is greater than the sum of positive charges.

 

polyatomic ions are eliminated   from the combination.

Question 8 (5 points)

All of the following ionic compounds are soluble in water, EXCEPT:

Question 8 options:

  

ammonium nitrate.

 

sodium sulfate.

 

aluminum hydroxide.

 

calcium carbonate.

Question 9 (5 points)

Which of the following best summarizes the solubility rule about the relationship between molecular structure and the formation of chemical compounds?

Question 9 options:

  

Like dissolves like.

 

Electricity and water don’t mix.

 

Elements on the same side of the   periodic table exchange electrons.

 

Solvents move through membranes   from higher solvent concentrations to lower.

Question 10 (5 points)

The EPA has established a legal limit or __________ for the concentration of nitrates, benzene, and other contaminants to our nation’s drinking water.

Question 10 options:

  

maximum contaminant level goal   (MCLG)

 

maximum contaminant   level (MCL)

 

municipal sanitary standard (MSS)

 

national toxicity requirement   (NTR)

Question 11 (5 points)

“Hard water” contains high concentrations of dissolved __________ ions.

Question 11 options:

  

cadmium and chromium

 

nitrate and lead

 

calcium and   magnesium

 

sodium and chloride

Question 12 (5 points)

Due to its prevalence in the environment and the severe and permanent neurological problems it causes, __________ is considered the most dangerous water contaminant.

Question 12 options:

  

Chromium

 

Mercury

 

Cadmium

 

Lead

Question 13 (5 points)

The oxides of sulfur and nitrogen are referred to as acids even though they contain no hydrogen ions because they:

Question 13 options:

  

lose electrons after being   combusted in car engines.

 

attract hydrogen atoms from   methane gas found in the atmosphere.

 

produce hydrogen ions once they   dissolve in water.

 

interact with ozone   to produce acid anhydrides.

Question 14 (5 points)

__________ includes wet forms such as rain, snow, fog, and cloud-like suspensions of microscopic water droplets often more acidic than acid rain.

Question 14 options:

  

Hydrogen deposition

 

Acid deposition

 

pH deposition

 

Aqueous deposition

Question 15 (5 points)

Even though there is relatively little sulfur dioxide in the smoggy air above Los Angeles, it still has quite acidic rain because:

Question 15 options:

  

sulfur dioxide drifts down from   Mt. St. Helen.

 

car engines are hot   enough to create nitrogen monoxide from internal combustion.

 

its proximity to the Pacific Ocean   allows the aqueous sulfur ions to be sucked into the atmosphere.

 

there are a number of coal-burning   power plants in the city to introduce sulfur into the atmosphere.

Question 16 (5 points)

A New York glass manufacturer was able to reduce NO emissions by 90% and energy consumption by 50% simply by:

Question 16 options:

  

switching from air   to oxygen in its large furnaces.

 

using electric power rather than   propane in heating the glass.

 

reducing the burning of   high-sulfur coal in its furnaces.

 

using silicon with a lower melting   point to make glass.

Question 17 (5 points)

__________ involves a chemical reaction of bacteria among certain plants that removes nitrogen from the air and converts it to ammonia.

Question 17 options:

  

Denitrification

 

Neutralization

 

Biological nitrogen   fixation

 

Nitrogen saturation

Question 18 (5 points)

The __________ clause in the Clean Air Act was aimed at requiring utility companies to implement air quality control meansures in older dirty plants once they were “substantially modified.”

Question 18 options:

  

New Source Review

 

Cap and Trade

 

Clear Skies   Initiative

 

National Acid Precipitation

Question 19 (5 points)

Milk of Magnesia is said to have a pH of 10 which is considered to be:

Question 19 options:

  

acidic.

 

basic.

 

neutral.

 

slightly acidic.

Question 20 (5 points)

The __________ ion originally became incorporated from seawater into ancient rocks such as coal, and when the coal is burned, it releases compounds that become acidic in the atmosphere.

Question 20 options:

  

sulfur

 

mercury

 

zinc

 

calcium

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