What Is the Source of the Acidic PH of Some

question 19

Multiple Choice

What is the source of the acidic pH of some mine runoff?

• A) Iron ores are reduced by exposure to the atmosphere.
• B) Pyrite is oxidized by exposure to the atmosphere and microbes.
• C) Iron ores contain sulfuric acid (H₂SO₄).
• D) Sulfur-containing ores are reduced by exposure to oxygen.
• E) Hydrogen gas trapped in ore reacts with the atmosphere to produce hydrochloric acid (HCl).

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Definitions:

Pure Rate of Interest

The rate of return on a risk-free investment, theoretically excluding the effects of inflation, default risk, and other factors.

Residual Claimants

Individuals or entities entitled to a share of an organization’s income only after all other claims, such as debts and taxes, have been satisfied.

Interest Rate

The cost of borrowing money, typically expressed as a percentage of the amount borrowed, paid to the lender.

MB = MC Rule

A principle in economics that states the optimal level of an activity is reached when the marginal benefit (MB) is equal to the marginal cost (MC).