Mg Cu mixture 22 g MgO CuO mixture 30 g

A mixture of Mg and Cu with a combined mass of 22 g was burned in oxygen, producing MgO and CuO with a combined mass of 30 g. How many grams of Cu was in the original mixture?

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Mg + Cu = 22 g 이므로,

Cu의 질량(g) = x 라 두면,

Mg의 질량(g) = (22 – x)

> Cu의 몰질량 = 63.55 g/mol

> CuO의 몰질량 = 79.55 g/mol

> 2Cu + O2 → 2CuO

---> Cu : CuO = 1 : 1 계수비(= 몰수비)

---> Cu의 몰수만큼, CuO가 생성된다.

(x g Cu) / (63.55 g/mol Cu) × (79.55 g/mol CuO)

= 1.2518x g CuO

( 참고: n=W/M https://ywpop.tistory.com/7738 )

> Mg의 몰질량 = 24.31 g/mol

> MgO의 몰질량 = 40.30 g/mol

> 2Mg + O2 → 2MgO

---> Mg : MgO = 1 : 1 계수비(= 몰수비)

---> Mg의 몰수만큼, MgO가 생성된다.

(22 – x Mg) / (24.31 g/mol Mg) × (40.30 g/mol MgO)

= (22 – x) / (24.31) × (40.30)

= (36.4706 – 1.6578x) g MgO

CuO + MgO = 30 g 이므로,

1.2518x + (36.4706 – 1.6578x) = 30

0.406x = 6.4706

x = 6.4706 / 0.406

= 15.9374 g

---> Cu의 질량

답: 15.9 g

Mg Zn mixture 1.0875 g MgO ZnO mixture 1.4090 g

[키워드] Mg Cu 혼합물 기준

Mg Cu mixture 22 g MgO CuO mixture 30 g