U.S. National Chemistry Olympiad 문제

U.S. National Chemistry Olympiad 문제

 

 

1998 Local Section Test #12

 

Hematite, Fe2O3, is the most common iron ore. How many moles of hematite are in an ore sample that contains 355 g of iron? Assume hematite is the only source of iron in this ore.

 

1) 1.11 mol

2) 1059 mol

3) 3.18 mol

4) 6.36 mol

 

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Fe의 몰질량이 55.85 g/mol이므로,

355 g Fe의 몰수는

355 g / (55.85 g/mol) = 6.36 mol Fe

 

Fe2O3 : Fe = 1 : 2 존재 비이므로,

Fe2O3 : Fe = 1 : 2 = ? : 6.36 mol

? = 6.36 mol / 2 = 3.18 mol Fe2O3

 

따라서 정답은 3번.

 

 

[키워드] 화학올림피아드, 화학 올림피아드