The melting point of the metal gallium is 30°C.

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1) QID: 1040
The melting point of the metal gallium is 30°C. Normal body temperature is about 37°C. When a person holds a piece of gallium, it tends to melt. This is an example of what type of change?

a change in composition
a physical change
a chemical change
a change in mass

(2) QID: 1042
Color, hardness, solubility, mass, density, volume, and melting point are all examples of what type of property of substances?

physical
chemical
intensive
extensive

(3) QID: 1043
The odor of a solution is an example of what type of measurement?

chemical
qualitative
quantitative
compositional

(4) QID: 1044
Table salt, or sodium chloride, melts at 801°C and boils at 1413°C. When table salt is melted and then boiled, what type of change(s) occur(s)?

chemical and physical changes
physical change only
chemical change only
neither chemical nor physical changes

(5) QID: 5751
True or false?
Since mass and volume are extensive properties, and density is the ratio of mass to volume, density is also an extensive property.

true
false

(6) QID: 8017
What is the general term for a factor that you can measure about matter that does not require a change of composition?

reactivity
flammability
physical property
chemical property

(7) QID: 8018
A physical property, such as mass or volume, that depends on the amount of matter, is called

an extensive property
a chemical property
an intensive property
water sensitivity

(8) QID: 8019
A qualitative measurement (as opposed to a quantitative measurement) is an analysis that yields descriptive, nonnumeric results. Which of the following is not a qualitative measurement?

color
taste
mass
odor

(9) QID: 8020
Which of the following is an extensive physical property?

temperature
mass
odor
melting point

(10) QID: 8021
Suppose that a man complains of feeling feverish. He says that he has an aching sensation in his joints and that he thinks he has a fever. He then uses a thermometer to find that he has a temperature of 101°F. The man’s descriptions of his condition are examples of what type(s) of measurement(s)?

quantitative measurement
qualitative measurement
quantitative and qualitative measurement
neither quantitative or qualitative measurements

 
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What is meant by the primary structure of a protein molecule?

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What is meant by the primary structure of a protein molecule? How
does it differ from the secondary structure of a protein? (2) How are secondary protein structures held together? (3) Discuss the importance of the tertiary and quaternary structures of proteins. Do all proteins have primary, secondary, tertiary, and quaternary structures? Explain. You must provide sufficient detail in your answer and incorporate information from the course materials to receive credit.

 
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Pentaerythritol tetranitrate, a.k.a., PETN,

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Pentaerythritol tetranitrate, a.k.a., PETN, is one of the most powerful
explosives known. It has a density of 1.77 g/cm3. Find (1) the volume of a 227 g (about 1/2 pound) quantity of the explosive before the explosion and (2) the volume of total gas produced after the explosion. Assume STP conditions:

C(CH2ONO2)4 (s) → 2CO(g) + 4H2O(g) + 3CO2(g) + 2N2(g)

All numbers immediately following elemental symbols are subscripts. You must show all work to receive credit. (HINT: You can use density to find the initial condition for volume of the solid. You can then use the mol of gaseous products to determine volume of final condition since you know molar volume at STP.)

 
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The chemical reaction will be opening a can of Guinness beer.

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The chemical reaction will be opening a can of Guinness beer. When
the can is opened, a small amount of beer and nitrogen, trapped in the widget, is forced out through the beer, which creates the famous creamy head that you find on a pint of Guinness Draught served in a pub. The widget gives Guinness Draught in cans the taste and texture of a pub-poured pint at home. should be at least 250 words.

(A). Identify a chemical reaction that affects your daily life. Include chemical formulas and equations.
(B). Is this a reaction that readily occurs in nature, or is it something that must be controlled and manipulated by man?
(C). What is/are the consequence(s) of this reaction? How can you tell this reaction has taken place?
(D). Is this reaction endo or exothermic / endo or exergonic (does it absorb heat or energy, or does it release it)?
(E). Is this reaction reversible?
(F). Classify this reaction. For example, is this a synthesis, decomposition, single displacement or double displacement reaction? Acid Base? Redox?

 
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