Balanced equations??

Question

a student is asked to give the sum of coefficients in the following balanced equation 3 FeO+2Al=Al2O3+ 3Fe. the student answer is i. why is the answer incorrect

Answer 1

Kayla - I have never seen Fe written as Fe₃, so I don't think that answer is correct...

The balanced equation is the original equation provided - but the sum of the coefficients is 9, not 7.  

 

There is a 3 in front of the FeO, a 2 in front of the Al, and then the other coefficients on the right are an unwritten 1 in front of the Al₂O₃, and a 3 in front of the Fe (plain old solid iron, not Fe₃).  

The sum of these numbers is 3 + 2 + 1 + 3 = 9.

Answer 2

Hi Kayla,

 

The correct balanced equation is 2Al + 3FeO = Al₂O₃ + Fe₃ It is a single replacement reaction.

The sum of coefficients is 2+3+1+1 = 7