# Temperature change boiling water

An iron cylinder is heated to 100.degrees C in boiling water ant then transferred to 145.0 grams of water in a 70.0 gram copper calorimeter at 20.0 degrees C. If the final temperature is 25.2 degrees C find the mass of iron used.

Would I use mL(Boiling water)+mcT(water)+mcT(coper calorimeter) +mcT (iron)???

And what would be negative?

Astronuc
Staff Emeritus
The iron will lose heat, so its temperature must decrease from 100°C to Tf = 25.2°C.

The 145 grams of water and the 70 g of copper in the calorimeter will experience a temperature increase from 20°C to Tf = 25.2°C.

Ok so is that the right equation because it keeps giving me a negative

Astronuc
Staff Emeritus
Try, mc$\Delta{T}$(water)+mc$\Delta{T}$(copper calorimeter) +mc$\Delta{T}$ (iron) = 0.