Answer:
[tex]Q_{iron} = -32730.083\,J[/tex]
Explanation:
By the First Law of Thermodynamics, the piece of iron and water reach thermal equilibrium when both have the same temperature. The heat released by the piece of iron is received by the water. That is to say:
[tex]Q_{iron} = -Q_{w}[/tex]
[tex]Q_{iron} = (93.64\,g)\cdot \left(4.186\,\frac{J}{kg\cdot ^{\textdegree}C} \right)\cdot (7\,^{\textdegree}C-90.5\,^{\textdegree}C)[/tex]
[tex]Q_{iron} = -32730.083\,J[/tex]
