The Most Abundant Metal in Earth's Crust Is Aluminum, Found

question 69

Multiple Choice

The most abundant metal in Earth's crust is aluminum, found mostly in the form of clays. There are no economical routes for extracting aluminum from clay. However, bauxite ore, impure hydrated aluminum oxide, is found in hot, humid regions, such as Australia, Guinea, and Brazil, and it can be purified and refined to make the metal. After the first purification step, hydrated aluminum oxide (Al₂O₃ . xH₂O) is obtained. When 100.0 g of this solid were heated, and the water driven off, 65.36 g of Al₂O₃ remained. How many water molecules (x in the molecular formula) were there in the hydrate?

• A)1
• B)2
• C)3
• D)4
• E)5

---

Definitions:

Average-Fixed-Cost Curve

A graphical representation showing how the fixed cost per unit changes with changes in the volume of production.

AVC Curve

The Average Variable Cost (AVC) curve represents how the per-unit variable cost of production changes as the quantity of output changes.

ATC Curve

The average total cost curve, which plots the per-unit total cost of producing goods at different levels of output.

Opportunity Cost

Represents the benefits that are missed or foregone when choosing one option over another.