Question

Chocolate begins to melt between 40°C and 45°C depending on the different components of chocolate. Assume that the melting temperature for chocolate is 43°C, and that heat transfer between the marshmallow and chocolate is perfectly efficient. Given this, to what temperature should you cool the roasted marshmallow (7.5 g) before adding it to the s'more so that the chocolate (50 g) is warmed up to 43°C from 25°C? Use 2 J/g⋅°C as the specific heat for both the chocolate and the marshmallow.

Enter the ideal temperature of the marshmallow in degrees Celsius

Answer 1

where is your work? The sum of heats gained is zero.
Heatmarshmellow+heatchco=0
7.5*c*(Tf-Ti)+59*c*(Tf-25)=0
Tf=43
Ti is the temp you have cooled the marsmellow before adding choc
Solve.