We can determine the purity of solid materials by using calorimetry. A gold ring (for pure gold, specific heat capacity = 0.1291 J g^-1 K^-1) with mass of 10.5 g is heated to 78.3 °C and immersed in 50.0 g of 23.7 °C water in a constant-pressure calorimeter. The final temperature of the water is 31.0 °C. Is this a pure sample of gold?