Answer:
Explanation:
Hello,
In this case, we notice that the energy gained by the first sample of water is lost by the second sample of water as they are heated and cooled respectively, therefore, in terms of heats:
Which in terms of masses, heat capacities and temperatures is:
In such a way, as the heat capacity is the same and the initial temperature of the cold water is required, we solve for it via:
With the given data we obtain:
Which means the second sample was hot.
Regards.
True a negative change in enthalpy means an exothermic reaction
<span>Strontium
hope this helps</span>
So, the short answer is: burning is irreversible because it involves a chemical reaction, while melting is reversible because it's just a phase change.