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A 542.5 sample g of manganese oxide has MnO ratio of 1.0 : 1.42 and consists of...

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lpzmch | Student, Undergraduate | eNotes Newbie

Posted July 4, 2012 at 10:51 PM via web

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A 542.5 sample g of manganese oxide has MnO ratio of 1.0 : 1.42 and consists of braunite (Mn2O3) and manganosite (MnO).

a) what masses braunite and manganosite are in the one?

b) what is the ratio of Mn^+3 : Mn^+2 are in the one?

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jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted July 24, 2012 at 1:36 PM (Answer #1)

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a)

Here ratio of Mn3O4:MnO=1.42:1.0

Therefore 1.42g of Mn3O4 consists 1.0g of MnO.

So in the sample mass of MnO = (1/1.42)*542.5g =382.04g

We have Mn2O3 and MnO in the Mn3O4 sample.

If weight of MnO is 382.04g,

Then weight of Mn2O3 = 542.5-382.04 = 160.46g

So;

mass of Manganosite = 382.04g

mass of Braunite = 160.46g

 

b)

Braunite (Mn2O3) have Mn^+3. One Mn2O3 gives two Mn^+3.

Manganosite (MnO) have Mn^+2. One MnO gives one  Mn^+2.

 

Mn2O3+MnO= Mn3O4

 

So we need two Mn^+3 and one Mn^+2 to form one Mn3O4.

Therefore;

Mn^+3:Mn^+2 = 2:1

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