A copper-nickel alloy of composition 50 wt% Ni-50 wt% Cu is slowly heated from a temperature of 1200°C (2190 °F). (a) At what temperature does the first liquid phase form? (b) What is the composition of this liquid phase? (c) At what temperature does complete melting of the alloy occur? (d) What is the composition of the last solid remaining prior to complete melting?

HELLO BELOW IS THE ATTACHED DIAGRAM USED TO ANSWER YOUR QUESTION AS IT WAS MISSING

A) 1270⁰c

B) 65%

C) 1320⁰c

D)  62%

Explanation:

Nickel alloy composition : 50 wt% Ni - 50 wt%

initial temperature = 1200⁰c = 2190⁰F

A) The temperature at which the first liquid phase form

from the attached diagram the temperature at which the first liquid if formed is 1270⁰c ( at point 2 )

B ) The composition of this liquid phase ( THE FIRST LIQUID )

the composition is found at point 3

wt % of Nickel = 35%, wt% of copper = 100 - 35 = 65%

C ) The temperature at which the alloy melts completely

from the attached diagram the temperature = 1320⁰c ( point 4 )

D)  The composition of the last solid remaining prior to complete melting

this can be gotten at point 5 and calculated as

wt % of Ni = 62%

wt % of Cu = 100 - 62 = 38%

i think it would be 5