How many moles of iron (iii) oxide are in a 120 gram sample of fe2o3?

First find the molar mass of Fe2O3, after you would want to do this
120 g Fe2O3 x 1 mol = # mol
Molar Mass

Thermodynamics are very important to understand for a number of reasons. The equation we use for specific heat is:

Q = m*s*(delta T)

Where Q is the heat, m is the mass of the substance, s is the specific heat of the substance, and (delta T) is the change in temperature.

To solve this problem, we will have to manipulate our equation to solve for m. After manipulating variables, we end with:

m = Q / [s * (delta T)]

Next, let’s organize ourselves and see what values the problem has given us:
- Q is 655J
- s is 2.46 J / g * °C
- (delta T) is 32.8 - 18.2 = 14.6°C
- m = ?

Now, all we need to do is plug in our values to solve for m:

m = (655J)/[(2.46J/g*°C)*(14.6°C)
m = 18.2 g

The mass of the ethanol sample is 18.2g.

Hopefully this helps you!