An alloy is an intimate association of two or more metals, with or without a definite composition, which has metallic properties. Heterogeneous alloys, such as tin-lead (Sn/Pb) solders, consist of a mixture of crystalline phases with different compositions. A homogeneous alloy with a unique composition having the lowest possible melting point is called a eutectic. A binary eutectic alloy is a mixture of two metals with a well-defined composition that melts at the lowest temperature of any composition of the mixture. The purpose of this project was to study the thermal properties of various compositions of Sn/Pb alloys. The conclusions from this work were as follows: (i) the eutectic composition was found to be 62 wt % Sn with a melting temperature of 183[degree]C; (ii) as the Sn and Pb compositions decreased from 100%, the alloy melting temperature also decreased; and (iii) by measuring the differential scanning calorimetry (DSC) peak melting point of the Sn/Pb alloy, the alloy composition can be obtained from the constructed binary phase diagram. Overall, the DSC provided a method of analysis for the determination of a binary alloy composition of Sn/Pb and the construction of a simple binary phase diagram. (Contains 1 table and 4 figures.)