To relate the change in temperature of a mass of certain material with the given heat, we can use the following equation:
[tex]q=m\cdot c\cdot\Delta T[/tex]Where q is the heat, m is the mass, c the heat capacity of the material and ΔT is the temperature variation.
So, we can solve for m and substitute the kown values:
[tex]m=\frac{q}{c\cdot\Delta T}=\frac{6290j}{0.900j/g\degree C\cdot(80.0-23.9)\degree C}=\frac{6290}{0.900\cdot56.1}g\approx125g[/tex]So, the mas of aluminium is approximately 125g.