Which set of steps is most typical of municipal drinking water purification in the U.S.?
|A)||ozonation, distillation, chlorination|
|B)||flocculation, filtration, chlorination|
|C)||ultraviolet light, ion exchange, filtration|
|D)||distillation, chlorination, ozonation|
Reverse osmosis, the process illustrated in this diagram, is a method used to
|A)||produce bottled mineral water, particularly in Europe.|
|B)||rediscover dissolved gold from sea water.|
|C)||remove dissolved solids from salt water.|
|D)||purify municipal drinking water supplies in areas with soft water.|
Which is a characteristic of a true solution?
|A)||Only one solute can be present in a given amount of solvent.|
|B)||The solute and solvent are present in equal amounts.|
|C)||The solute cannot be separated from the solvent by simple filtration.|
|D)||The solute must be a solid and the solvent a liquid.|
What is the molarity of a solution containing 3.5 moles of HCl in 5.0 L of solution?
Which statement is true for a calcium ion?
|A)||number of protons = 20, number of electrons = 22, net charge = 2+|
|B)||number of protons = 20, number of electrons = 18, net charge = 2-|
|C)||number of protons = 20, number of electrons = 22, net charge = 2-|
|D)||number of protons = 20, number of electrons = 18, net charge = 2+|
Which is the experimental H-to-O-to-H bond angle in a water molecule?
The gasoline additive MTBE has caused problems by contaminating ground water in some areas of the country where oxygenated fuels are required. What property of MTBE makes this problem worse?
|A)||MTBE is a nonpolar molecule and dissolves well in nonpolar soils, where it can leach into the ground water.|
|B)||MTBE is very volatile, and escapes into the air when gasoline is pumped. MTBE can then be washed into the soil by acid rain.|
|C)||MTBE is a polar molecule and, if oxygenated gasoline is spilled onto the ground, the MTBE dissolves into ground water.|
|D)||MTBE is not soluble in oxygenated gasolines, and therefore is never burned with the rest of the fuel.|
Most of the earth's fresh water supply is found
|A)||in the oceans.|
|B)||in plant material.|
|C)||as clouds in the atmosphere.|
|D)||in ice caps, glaciers, and ground water.|
This diagram represents water molecules arranged in the liquid state. To what kind of bonding forces does the arrow point?
|A)||a covalent bond, a type of intramolecular force|
|B)||a covalent bond, a type of intermolecular force|
|C)||a "hydrogen bond," a type of intramolecular force|
|D)||a "hydrogen bond," a type of intermolecular force|
Which federal agency regulates the quality of bottled water in the U.S.?
|A)||U.S. Food and Drug Administration, FDA|
|B)||U.S. Environmental Protection Agency, EPA|
|C)||U.S. Occupational Safety and Health Administration, OSHA|
|D)||U.S. Department of Agriculture, USDA|
Numbers 1 - 4 are used to identify four different elements. Based on trends within the periodic table, which element is expected to have the greatest tendency to attract bonded electrons?
The MCLG for the nitrate ion in drinking water is 10 ppm. Express this value as a percentage.
|A)||1.0 x 105%|
|B)||1.0 x 103%|
|C)||1.0 x 10-2%|
|D)||1.0 x 10-3%|
Beer is a complex aqueous solution. For example, one brand has 7% by weight of ethanol. Ethanol has a formula weight of 46 g/mol. One liter of the 7% beer contains 62 g of ethanol. What is the approximate molarity of ethanol in this beer?
Which is true concerning chlorine molecules in water?
|A)||Chlorine serves as an inexpensive, easily delivered, and persistent anti-bacterial in water.|
|B)||Chlorine reacts with small, naturally-occurring molecules in water to form halogenated organics.|
|C)||Chloroform and ozone are alternatives in current use as anti-microbial agents in water.|
|D)||Statements A and B are true.|
Which mechanism(s) help explain how lead ions find their way into drinking water?
|A)||residual lead (lead salts) from "leaded" gasoline that was burned during the 1950s, 1960s, and 1970s|
|B)||lead in pipes or connections between pipes|
|C)||lead leached from the soil as the result of chlorine in the water (formation of lead chloride salts)|
|D)||All of these are primary mechanisms for the delivery of lead into drinking water.|