The answer is dissolved in water, because in chemistry, (aq) is shorthand for aqueous solution.
Answer:

Explanation:
The specific heats of water and steel are


Assuming that the water and steel are into an <em>adiabatic calorimeter</em> (there's no heat transferred to the enviroment), the temperature of both is identical when the system gets to the equilibrium
An energy balance can be written as
Replacing

Then, the temperature 
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