6X(s) + 2B2O3(s) → B4X3(s) + 3XO2(g). 165 g X 2.29 mol B4X3

6X(s) + 2B2O3(s) → B4X3(s) + 3XO2(g). 165 g X 2.29 mol B4X3

 

 

Consider the following reaction, where X represents an unknown element:

6X(s) + 2B2O3(s) → B4X3(s) + 3XO2(g)

If 165 g of X reacts completely with diboron trioxide

to produce 2.29 mol of B4X3, what is the identity of X?

 

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6X(s) + 2B2O3(s) → B4X3(s) + 3XO2(g)

 

X : B4X3 = 6 : 1 = 계수비(= 몰수비) 이므로,

2.29 mol B4X3 생성에 필요한 X의 몰수를 계산하면,

 

X : B4X3 = 6 : 1 = ? mol : 2.29 mol

 

? = 6 × 2.29 = 13.74 mol X

 

 

 

몰질량, M = W / n

( 참고 https://ywpop.tistory.com/7738 )

 

= 165 g / 13.74 mol

= 12.01 g/mol

---> 답은 C, Carbon.