Find out of the friend is getting a good deal I have a strange chemistry question that I've never came across before, and I have no idea about how to solve it.


  Your friend comes across a good deal to purchase a gold ring. She asks you for advice for you to test the ring. The ring has a mass of 4.54 g. When the ring is heated with 94.8 J of energy, temperature rises from 23.0 °C to 47.5 °C. The gold specific heat capacity is 0.1291 J/g. Is she getting a good deal?


So I did the equation to solve for Q which is 14.35 J, and I have all the numbers the (considering they are given) but I have no idea how to actually calculate how much of this ring is pure gold. 

I came here as a last resort.
The jewelry gold usually comes historically rated in grades 14 or 18 karats, where 24 means pure gold. The rest is mostly silver.

Find out specific heat capacity for the complementary metals like silver or copper, so you could roughly estimate via interpolation.

Another method would be pyknometry, determining the ring density by differential weighting the mass of displaced water - old good method of Archimedes. Gold has almost double density, compared to other expected metals.

Edit:  list of densities:


Gold 19.3. 
Silver 10.5.


If linearly interpolated by mass fraction:.    


14 karat gold  15.63.
18 karat gold  17.1