1. Use the phase diagram from the lecture notes on the water sugar system. You start...

 

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1. Use the phase diagram from the lecture notes on the water sugar system. You start off with a 100 g mixture of 70 wt% sugar and 30 wt% water, heat above the solubility limit to dissolve the sugar, and then cool the mixture down to room temperature (~20 C). a. Once the mixture reaches equilibrium, what is the composition of the syrup? b. Use the lever rule to determine how much rock candy (mass in grams of 100% crystalline sugar) will be made. 2. Using the attached phase diagram, calculate the mass of each phase present in 1 kg of a 30:70 Ni-Cu alloy at 1300 C, 1225 C, and 1150 C and the composition of the phases. Note: A higher magnification of a portion of the Ni-Cu phase diagram is shown directly below the full phase diagram. 3. A hypothetical A-B alloy of composition 55 wt% A at some temperature is found to consist of mass fractions of 0.5 for both a and phases. If the composition of the phase is 90 wt% B and 10 wt% A, what is the composition of the a phase? 4. For the spontaneous melting of body-centered cubic (BCC) titanium into liquid titanium, list whether the following quantities are negative, zero, or positive and state your reasoning. a. The change in Gibbs free energy, AG b. The change in entropy, AS c. The change in enthalpy, AH 5. At atmospheric pressure, a 40:60 Pb-Sn alloy exists as two phases, a lead-rich solid and a tin- rich liquid. Calculate the degrees of freedom for this alloy and comment on its practical significance. 1. Use the phase diagram from the lecture notes on the water sugar system. You start off with a 100 g mixture of 70 wt% sugar and 30 wt% water, heat above the solubility limit to dissolve the sugar, and then cool the mixture down to room temperature (~20 C). a. Once the mixture reaches equilibrium, what is the composition of the syrup? b. Use the lever rule to determine how much rock candy (mass in grams of 100% crystalline sugar) will be made. 2. Using the attached phase diagram, calculate the mass of each phase present in 1 kg of a 30:70 Ni-Cu alloy at 1300 C, 1225 C, and 1150 C and the composition of the phases. Note: A higher magnification of a portion of the Ni-Cu phase diagram is shown directly below the full phase diagram. 3. A hypothetical A-B alloy of composition 55 wt% A at some temperature is found to consist of mass fractions of 0.5 for both a and phases. If the composition of the phase is 90 wt% B and 10 wt% A, what is the composition of the a phase? 4. For the spontaneous melting of body-centered cubic (BCC) titanium into liquid titanium, list whether the following quantities are negative, zero, or positive and state your reasoning. a. The change in Gibbs free energy, AG b. The change in entropy, AS c. The change in enthalpy, AH 5. At atmospheric pressure, a 40:60 Pb-Sn alloy exists as two phases, a lead-rich solid and a tin- rich liquid. Calculate the degrees of freedom for this alloy and comment on its practical significance.