Answer:
5444.89 grams of Fe
Explanation:
1) We need the chemical equation for Fe3O4 to find the mole ratio for Fe to Fe3O4. Chemical equation:
3Fe+4H2O → Fe3O4+4H2
The mole ratio of Fe to Fe3O4 is 3:1
2) Now, we find how many grams of Fe are needed to produce 32.5 moles of Fe3O4.

= 97.5 moles Fe needed to produce 32.5 moles of Fe3O4
3) Convert 97.5 moles of Fe into grams. The molar mass of Fe is 55.845g.

= 5444.8875g or 5444.89g.
Answer:
-6.27 kj
Explanation:
Given data:
Energy released = ?
Mass of steam = 15 g
Initial temperature = 100°C
Final temperature = 0°C
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 j/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 0°C - 100°C = -100°C
Q = 15g × 4.18 j/g.°C × -100°C
Q = -6270 j
J to KJ:
-6270 j/1000 = -6.27 kj
Difference between Gas and Vapour:
Gas:
A thermodynamic state in which a substance exists only in one phase i.e. Gas phase. In above given examples N₂, He and CO₂ exists as gases at room temperature. These gases cannot form a solid or liquid phase along with gas phase as these states requires very low temperatures.
Vapours:
It is a thermodyanamic state in which a substance exists in more than one phase. In given options Sulfur can exist in vapor state. This is because sulfur exists in a cyclic or chain form due to catenation (self linkage property). Therefore, a lower members of S allotrops can form a vapours.