XI3 0.5000 g XCl3 0.2360 g

XI3 0.5000 g XCl3 0.2360 g

XI3 0.5000 g을 사용하여 XCl3 0.2360 g을 얻었다.

 

 

An element X forms an iodide (XI3) and a chloride (XCl3).

The idodie is quantitatively converted to the chloride

when it is heated in a stream of chlorine:

2XI3 + 3Cl2 → 2XCl3 + 3I2

If 0.5000 g of XI3 is treated, 0.2360 g of XCl3 is obtianed.

a) Calculate the atomic weight of the element X.

b) Identify the element X.

 

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n = W / M

( 참고 https://ywpop.tistory.com/7738 )

 

 

 

XI3의 몰수를 계산하면,

n = 0.5000 g / [(x + 380.71) g/mol]

 

 

 

XCl3의 몰수를 계산하면,

n = 0.2360 g / [(x + 106.36) g/mol]

 

 

 

2XI3 + 3Cl2 → 2XCl3 + 3I2

XI3 : XCl3 = 1 : 1 계수비(= 몰수비) 이므로,

XI3의 몰수 = XCl3의 몰수

 

 

 

0.5000 g / [(x + 380.71) g/mol] = 0.2360 g / [(x + 106.36) g/mol]

0.5000 / (x + 380.71) = 0.2360 / (x + 106.36)

 

0.5000(x + 106.36) = 0.2360(x + 380.71)

0.5000x + 0.5000(106.36) = 0.2360x + 0.2360(380.71)

(0.5000 – 0.2360)x = 0.2360(380.71) – 0.5000(106.36)

 

x = [0.2360(380.71) – 0.5000(106.36)] / (0.5000 – 0.2360)

= 138.89 g/mol

---> Lanthanum, La, 란타넘