Chemistry - Masses with moles. (1 Viewer)

[beve]

Moles has been fine for me so far, my class is working out of Conquering Chemistry 3rd Edition. It's a pretty ordinary textbook.. but our school is a bit pov. So anyway, I digress. Gotten up to questions like this:

What mass of Zinc is formed when 0.2 mole Zinc Oxide reacts with excess carbon.

Wikipedia tells me that the reaction should go

ZnO + C ---> Zn + CO

But as to where to go after that.. I'm stumped. Theres a whole section of questions like this so I'd appreciate it if someone could explain it to me.... *puppy dog eyes*

 

[ahhliss]

I don't know the reaction so I'll go with what you've got.
It's balanced and the ratio is 1:1:1:1 so if there are 0.2 moles of Zinc Oxide, then everything is 0.2 moles. So just find the mass of 0.2 moles of Zinc.

 

[beve]

the answer says it's 0.3 -

how do i get to that?

 

[Continuum]

The book lies, it should be 0.2 moles (according to that chemical equation you gave us).

 

[ahhliss]

o.0 I got the mass of zinc to be 13.08g... I did 0.2*65.39.

 

[JSBboag]

M(Zn) = ?
n(ZnO) = 0.2mol
n(Zn) = 0.2mol (same ratio 1:1)
n(Zn) = m/M
m(Zn) = 0.2 x 65.41
m(Zn) = 13.082g

 

[kaz1]

The book is probably using a differnet equation if it gives you a differnet answer because 13.08g is correct according to that equation.

 

[benji6667]

ZnO (s) + C (s) --> Zn (s) + CO (g)

All the species in this reaction are in a 1:1 ratio

So the number of moles of ZnO = number of moles of Zn

Therfore Number of Moles (Zn) = 0.2

Calculating Mass:

N = M / MM

MM = 65.39

M = N * MM
= 0.2 * 65.39

=13.08g of Zn Metal

 

[beve]

yeah book had wrong answer and it threw me. cheers all

 

[aimzlouise]

yeah book had wrong answer and it threw me. cheers all

hey which question in the book is it? because i have the same book, coz my school pov as well