The answer is 4.0 moles of magnesium
because...
..
...4.0mol Makmol O2 =3.0mol O2
Answer:
297 J
Explanation:
The key to this problem lies with aluminium's specific heat, which as you know tells you how much heat is needed in order to increase the temperature of 1 g of a given substance by 1∘C.
In your case, aluminium is said to have a specific heat of 0.90Jg∘C.
So, what does that tell you?
In order to increase the temperature of 1 g of aluminium by 1∘C, you need to provide it with 0.90 J of heat.
But remember, this is how much you need to provide for every gram of aluminium in order to increase its temperature by 1∘C. So if you wanted to increase the temperature of 10.0 g of aluminium by 1∘C, you'd have to provide it with
1 gram0.90 J+1 gram0.90 J+ ... +1 gram0.90 J10 times=10×0.90 J
However, you don't want to increase the temperature of the sample by 1∘C, you want to increase it by
ΔT=55∘C−22∘C=33∘C
This means that you're going to have to use that much heat for every degree Celsius you want the temperature to change. You can thus say that
1∘C10×0.90 J+1∘C10×0.90 J+ ... +
