What is the mass of 2.56 × 10–4 moles of Fe2O3?

A. 4.09 × 10–2 g

B. 159.6 g

C. 6.23 × 105

D. 1.60 × 0–6 g

Question

What is the mass of 2.56 × 10–4 moles of Fe2O3?

 A. 4.09 × 10–2 g  
 
 B. 159.6 g  
 
 C. 6.23 × 105  
 
 D. 1.60 × 0–6 g

anonymous · Answer

first find the molecular weight of Fe2O3

anonymous · Answer

molecular weight of Fe2O3 =56*2 +16*3 =112+48=160

anonymous · Answer

now by definition of mole 
1 mole of Fe2O3 weighs 160 g

anonymous · Answer

hence 
2.56 × 10–4 moles of Fe2O3 must weigh   2.56 × 10–4 * 160 g....

ash2326 · Answer

@Joshyface I think this should be posted in Chemistry. Please post chemistry question in Chemistry subject now onwards. http://openstudy.com/study#/groups/Chemistry

anonymous · Answer

@@Joshyface 
its 2.56*160/10000 g = 4.09 × 10–2 g 
so option A