Sand Is Converted to Pure Silicon in a Three Step

question 7

Multiple Choice

Sand is converted to pure silicon in a three step process. The third step is
SiCl₄(g) + 2Mg(s)  2MgCl₂(s) + Si(s) H = -625.6 kJ
What is the enthalpy change when 25.0 mol of silicon tetrachloride is converted to elemental silicon?

• A) -25.0 kJ
• B) -7820 kJ
• C) -1.56 × 10⁴ kJ
• D) -3.13 × 10⁴ kJ
• E) none of the above

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Definitions:

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Electronics Company

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Lower Control Limit

The lowest boundary in control charts that indicates the threshold below which a process may be out of control.

Population Mean

The average value of a set of characteristics within an entire population.