Decide why the heat from a candle flame is barely tolerable when a person places his or her hand above the candle compared to when the hand is placed next to the candle
Question 1
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Decide why the heat from a candle flame is barely tolerable when a person places his or her hand above the candle compared to when the hand is placed next to the candle.
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The highest temperature is at the tip of the candle flame. |
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Hot air rises upward, not sideways, by the mechanism of convection. |
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Hot air rises upward, not sideways by the mechanism of conduction. |
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The highest temperature is at the base of the candle flame. |
Question 2
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The fuel used in some racing cars contains isoamyl nitrite. Select which one of the characteristics below is classified as a chemical change/property?
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Isoamyl nitrite is a yellowish liquid having an ethereal odor. |
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At 77°F (25°C) isoamyl nitrite has a specific gravity in the range 0.865-0.875. |
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Isoamyl nitrite is nearly insoluble in water. |
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Isoamyl nitrite decomposes when exposed to light. |
Question 3
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An ionic or covalent compound that is used commercially in the form of a homogeneous mixture of two or more substances is called a:
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solvent. |
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solute. |
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solution. |
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substance. |
Question 4
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The lead (Pb) concentration detected from a water-supply well is 0.15 mg/l (assume specific gravity of the well water is 1.0 at 25 deg C). If the drinking water standard is 15 ppb, what is your evaluation of this data?
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The Pb concentration is equivalent to 0.015 ppb and therefore meets the drinking water standard. |
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The Pb concentration is equivalent to 15 ppb and therefore meets the drinking water standard. |
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The Pb concentration is equivalent to 150 ppb and therefore does not meet the drinking water standard. |
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The Pb concentration is equivalent to 1,500 ppb and therefore does not meet the drinking water standard. |
Question 5
1.
An emergency responder produces up to 1.575 L/hr of perspiration when strenuously exercising. How long must an emergency responder exercise to produce one quart of perspiration?
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30 minutes |
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36 minutes |
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40 minutes |
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46 minutes |
6. The relative reactivity rating of a substance is denoted by a numeric code in the __________ quadrant of its NFPA hazard diamond.
7. The vaporization of the liquid elements of gasoline constitutes a __________ change.
8. _________ is either absorbed or emitted when there is a change in the physical state of a substance such as ice that is melting.
9. Radon, which is a radioactive gas, is a member of the __________ gas family. Name one other element in this group or family: __________.
10. The spread of fire from the ground floor to an upper floor of a building is primarily due to heat transfer by __________ and __________.
******Your total response to parts a-d must be at least 200 words in length.******
11.You are the project manager of an environmental company that was hired to cleanup a historical arsenic contamination site. Soil sampling results indicated the area impacted with arsenic above action levels is 30 feet by 55 feet. The depth of the arsenic plume is three feet below ground surface. The land owner wanted to clean this site for future development. Answer the questions below to help you prepare a cost estimate for this portion of the project. Your solutions and any assumptions to justify your estimate must be shown.
a. What is the chemical symbol of arsenic, and what group/family does it belong to?
b. Solve for the minimum volume of soil that will be excavated in cubic yards?
c. If each dump truck can transport 18 cubic yards, determine how many dump trucks loads will be transported? For calculation purposes, add a 15% “fluff factor” (add to the volume that will be transported).
d. If the bulk density of soil is 1350 kg/m3 (84.3 lb/ft3), solve for the weight of the soil that will be transported to a disposal site in kilograms?
12. The Global Harmonization System of Classification and Labeling of Chemical Substances (GHS) has been adopted by the Occupational Safety and Health Administration (OSHA) and the Department of Transportation (DOT).
a. Describe what GHS is.
b. In your opinion, what are the benefits and drawbacks of this system?
Your response must be at least 200 words in length.
