PHYSICAL SCIENCE 102 HWKEVAL#4[g]
CURRENT DATE and TIME

A chemical mixture is distinguished from a chemical compound in that

Your answer:
there are no chemical bonds within a chemical mixture.
the properties of a chemical mixture are unique and unlike that of any of the components
there is no significant difference between the two.
chemical compounds may be found in a chemical mixture.


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The components of a mixture are most efficiently separated from one another based upon their

Your answer:
similarities in chemical properties.
similarities in physical properties.
differences in physical properties.
differences in chemical properties.


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The mass of a nucleon is greatest where its potential energy is

Your answer:
least.
greatest.


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Read carefully. Twice as much as one million trillion is two million trillion. One thousand times as much is 1000 million trillion. One million times as much is 1,000,000 million trillion, which is the same as one trillion trillion. Thus, one trillion trillion is a million times greater than a million trillion. Got that? So how many more water molecules than impurity molecules are there in a glass of water that is 99.9999% pure?

Your answer:
1000 (one thousand: 1 x 10³) more water molecules than impurities molecules.
1,000/000/000 (one billion: 1 x 10⁹) more water molecules than impurities molecules.
1,000,000 (one million: 1 x 10⁶) more water molecules than impurities molecules.
1,000,000,000,000,000,000 (one million trillion: 1 x 10¹⁸) more water molecules than


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Someone argues that he or she doesn't drink tap water because it contains thousands of molecules of some impurity in each glass. How would you respond in defense of the water's purity, if it indeed does contain thousands of molecules of some impurity per glass?

Your answer:
There's no defense. If the water contains impurities it should not be drunk.
Impurities aren't necessarily bad, in fact, they may be good for you.
The water contains water molecules and each water molecule is pure.
Compared to the billions and billions of water molecules, a thousand molecules of


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Many dry cereals are fortified with iron, which is added to the cereal in the form of small iron particles. How might these particles be separated from the cereal?

Your answer:
collect the iron filings with a magnet
heat the cereal so that the iron particles melt and thereby coalesce
add water and the iron particles will float to the top
blend the cereal to a fine consistency and pass through a filter


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Half-frozen fruit punch is always sweeter than the same fruit punch completely melted because

Your answer:
the sugar sinks to the bottom.
the half-frozen fruit punch is warmer.
crystallization is a purifying process.
sugar molecules arc less soluble in a half-frozen solution.


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By what means can a solution and a suspension be distinguished?

Your answer:
A suspension is heterogeneous while a solution is homogeneous.
A solution can be transformed into a suspension but a suspension cannot be transformed
A suspension can be transformed into a solution but a solution cannot be transformed into
A suspension will separate into different phases when centrifuged.


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Fissioning helium would yield a net

Your answer:
absorption of energy.
neither absorption nor release of energy
release of energy.


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What do chicken noodle soup and garden soil have in common?

Your answer:
They are both examples of compounds.
They both contain elements.
They are both examples of heterogeneous mixtures.
nothing


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Classify the following as element, compound, or mixture: table salt, stainless steel, table sugar, aluminum, ice.

Your answer:
compound, element, compound, element, compound
compound, mixture, compound, element, compound
mixture, compound, mixture, element, compound
none of these
mixture, element, compound, element, element


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The density of water is 1.0 g/mL. Calculate the number of moles of water present in a swimming pool containing 8.50 x 10⁴ liters of water.

Your answer:
none of these
2 x 10² mol
4 x 10⁶ mol
3 x 10⁵ mol
5 x 10⁴ mol


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A student prepares a solution by dissolving 4.75 g of solid KOH in enough water to make 275 mL of solution. Calculate the molarity of the KOH solution.

Your answer:
0.308 M
1.101 M
0.764 M
0.140 M
none of these


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Continued from #13.......What percent of the solution is water(assume the density of water = 1 g/mL)?

Your answer:
15.7
none of these
1.7
98.3
84.3


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Groundwater can be contaminated by bacteria and other pathogens that seep from septic tanks, broken sewer lines, and barnyard wastes. In many instances, however, this is not a serious health problem even in the presence of a large population. Why?

Your answer:
none of these
Most municipalities have alert systems to warn people of an outbreak.
The diseases spread by these pathogens are not typically contagious.
Without sunlight, the pathogens generally die out
The soil itself may serve to filter out the pathogens.


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Where does most of the solid mass of raw sewage end up after being collected at a treatment facility?

Your answer:
none of these
It is buried in landfills.
It is injected into the water table.
It is sold to farmers for fertilizer.
It is tapped for the generation of methane gas.


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