Some Pure Metals Can Be Obtained from Their Ores Simply

question 92

Multiple Choice

Some pure metals can be obtained from their ores simply by heating to a high temperature to drive off the oxygen, but iron ore usually is refined by reacting it with carbon monoxide. Use the information in the following table to determine whether or not iron ore could be refined by heating to a high temperature and, if so, how high the temperature must be. The oxidation reaction producing iron ore is given below. Thermodynamic Properties

• A)Iron ore cannot be refined by heating because the oxidation reaction is spontaneous in the forward direction at all temperatures.
• B)Iron ore could be refined by heating, but temperatures in the range 500-1,000 K are needed.
• C)Iron ore could be refined by heating, but temperatures in the range 2,000-3,000 K are needed.
• D)Iron ore could be refined by heating, but temperatures in the range 1,000-2,000 K are needed.
• E)Iron ore could be refined by heating, but the temperature must be greater than 3,000 K.

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Definitions:

Marginal Utility

The extra pleasure a customer receives from using an additional unit of a product or service.

Consumer Surplus

The discrepancy between the amount consumers are prepared to pay for a product or service and the actual price they pay.

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A measure of satisfaction, usefulness or value that a consumer receives from any good or service.

Utility

In economics, the total satisfaction received from consuming a good or service.