PHYSICAL SCIENCE 102 HWKEVAL#3[g]
CURRENT DATE and TIME

Which set of coefficients balance the following chemical equation?



__B₂O₃ + ____C → __B₄C₃ + __CO₂

Your answer:
1,6,2,3
2,6,1,3
2,3,1,3
2,6,1,1


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Which set of coefficients balance the following chemical equation?



__AlO₃H₃ → __Al₂O₃ + __H₂O

Your answer:
4,2,6
2,1,3
1,3,2
8,4,5


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Which set of coefficients balance die following chemical equation?



__NaClO₃ → __NaCl + __O₂

Your answer:
2,2,3
1,1,1
1,1,2
2,2,5


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The proper name for the chemical compound NH₄NO₃ is

Your answer:
ammonium nitrate.
ammonium nitrogen trioxide.
dinitrogen hydride trioxide.
nitrogen tetrahydride nitrate.


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The systematic names for water, ammonia, and methane are dihydrogen monoxide, H₂O; trihydrogen nitride, NH₃; and tetrahydrogen carbide, CH₄. Why do most people, including chemists, prefer to use the common names for these compounds?

Your answer:
all of the above
These compounds are encountered frequently.
The common names are shorter and easier to pronounce.
The common names are more widely known.


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The purpose of coefficients in chemical equations is to make

Your answer:
the equation balance by splitting the chemical formula.
the number of times each element appears as a reactant and as a product the same.
the number of molecules of reactants and products equal.
all the subscripts within the chemical formula equal.


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To say a chemical equation is balanced means the

Your answer:
number of molecules of reactants and products are equal.
subscripts on both sides of the reaction add up to the same number.
number of times each element appears as a reactant is equal to the number of times it
coefficients on both sides of the reaction add up to the same number.


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A chemical mixture is distinguished from a chemical compound in that

Your answer:
chemical compounds may be found in a chemical mixture.
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.


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When two different elements combine to form a compound the resulting properties of the compound are

Your answer:
predictable based upon the nature of the combining elements.
not necessarily anything like those of the elements.
most like the element given in the greatest amount.
about the average of the properties of the two elements.


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

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


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Which set of coefficients balance the following chemical equation?



__Al +__O₂ → __Al₂O₃

Your answer:
2,3,1
2,3,2
4,3,2
4,6,2


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Which set of coefficients balance the following chemical equation?



__N₂ + __H₂ → __NH₃

Your answer:
1,3,1
2,3,4
1,1,2
1,3,2


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Which set of coefficients balance the following chemical equation?



__MgO +__Fe → __Fe₂O₃ + __Mg

Your answer:
3,4,1,3
1,2,1,3
1,2,3,3
3,2,1,3


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Which set of coefficients balance the following chemical equation?



__PH₃ + __O₂ → __P₄O₁₀ + __H₂O

Your answer:
2,8,1,3
4,6,1,3
4,8,1,6
2,4,1,6


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If you eat metallic sodium or inhale chlorine gas, you stand a strong chance of dying. Let these two elements react with each other, however, and you can safely sprinkle the compound on your popcorn for better taste. What is going on?

Your answer:
Sodium and chlorine from the elemental form is more concentrated than the sodium and
All elements are inherently dangerous.
After these two elements react they lose the potential energy to cause harm.
Sodium chloride has nothing in common with sodium and chlorine.


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The proper name for the chemical compound N₂O is

Your answer:
dinitrogen oxide.
nitrogen nitrate.
nitrogen dioxide.
nitrogen oxide.


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The name for the chemical compound of the formula NaNO₃ is

Your answer:
sodium trinitrate.
sodium nitrogen trioxide.
sodium nitrate.
sodium nitrogen oxide.


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Which elements are some of the oldest known? What is your evidence? The oldest known elements are the ones with

Your answer:
atomic symbols that match their modern names.
the lowest atomic numbers.
odd looking atomic symbols.
the highest atomic numbers.


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Oxygen atoms are used to make water molecules. Does this mean that oxygen, O₂, and water, H₂O, have similar properties? Why do we drown when we breathe in water despite all the oxygen atoms present in this material?

Your answer:
Yes, and this explains how fish are able to breathe water.
Yes, but that their properties are similar is only a coincidence.
No, compounds are uniquely different from the elements from which they're made.
No, but their similar properties are only a coincidence.


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