Homework Help: grade 12 chem - check my answer again please

Posted by Sarah H on Saturday, May 24, 2008 at 9:01pm.

Hi, please check my work:
In an experiment, 23.4 g of FES are added to excess oxygen and 16.5 g of FE2O3 are produced. The balanced equation is:
4FeS + 7O2 --> 2Fe2O3 + 4SO2
Calculate the % yield.

My Answer:
nFeS=23.4g/87.92 g/mol
=0.266 mol

4mol FeS / 0.266 mol = 7mol O2/ x02
xO2=0.466 mol

mFe2O3 = nXM
= 0.466 mol x 159.7 g/mol
= 74.4 g

% yield = actual yield / theoretical yield X 100%
=16.5 g/74.4 g x 100%
=22.2%

Responses

gr. 12 chemistry - drwls, Saturday, May 24, 2008 at 5:08pm
That equation does not look balanced to me. Check the oxygen on both sides.

-this was the balanced equation out of the textbook...i can't believe the textbook's wrong (again)...

grade 12 chem - check my answer again please - bobpursley, Sunday, May 25, 2008 at 8:02am
you should get half the moles you started with.

expected yield=.133 moles or .133*molmassFe2O3

percentyield=molesproduct/expectedmoles

= (16.5g/159.7)/(.133)
= about 77 percent

check that thinking. In your second step you solve for xO2. Why?

Answer this Question

Related Questions

gr. 12 chemistry - Hi, please check my work: In an experiment, 23.4 g of FES are...
Chemistry - please help - Hi, please check my work: In an experiment, 23.4 g of ...
Chemistry - please help - Hi, please check my work: In an experiment, 23.4 g of ...
Chemistry - Bob Pursley - Posted by Sarah H on Friday, May 23, 2008 at 8:10pm. ...
Chemistry - Please be specific. In an experiement 23.4 g of iron sulphide, FeS ...
Math please check answer - please check my answer :) The monthly payment of a $...
CHemistry....Please double check DrBobb - What mass of ethylene glycol C2H6O2, ...
Algebra - Hello, can someone tell me if I got the following solve and check work...
Math please check answer - please check my answer thanks What would be the ...
MAT 7th GRADE - Please help. Will someone please check the answer to these ...

For Further Reading

First Name:
School Subject:
Answer: