Step 1 - Understanding the problem
Heating silver can provoke two different physical transformations: raising its temperature or a physical change. A physical change (like solid to liquid) can only happen at the melting (or boiling) point of a substance in atmospheric pressure.
So here's the plan: we will calculate the amount of heat that was absorded when raising the temperature from 130°C to 961°C and then we will calculate the energy required to turn solid silver at 961°C in liquid silver at this same temperature.
Step 2 - Calculating the heat involved in raising the temperature
Heat is related to temperature change by the following formula, in which Q represents the heat, m the mass, c the specific heat and delta T the temperature variation:
[tex]Q=mc\Delta T[/tex]
We already know that m = 28g, c = 0.235 J.g/°C and delta T = 831 °C, therefore:
[tex]Q=28\times0.235\times831=5467.98=5.46798KJ[/tex]
Step 3 - Calculating the heat involve in the phase transition
In the phase transition, since there's no temperature variation, we just have to multiply the mass by the heat of fusion:
[tex]Q=m\times heat\text{ of fusion}[/tex]
We know that m = 28g and heat of fusion = 11.3 kJ/g, so:
[tex]Q=28\times11.3=316.4KJ[/tex]
Step 4 - Summing the energies
Now we just have to sum it up:
[tex]Q_{total}=5.46798+316.4=321.86798KJ[/tex]
And that's the total heat involved in this process: 321.86798 KJ.
