An aluminum saucepan weighing 1.5 kg contains 800 g of water at room

An aluminum saucepan weighing 1.5 kg contains 800 g of water at room temperature. (20) How much boiling water must be added to get 45?

When adding boiling water, it will give off heat to both the water and the pan:

Qreceived = c (aluminum) * m (pans) * (t2 –t1) + c (water) * m (water in a pan) * (t2 –t1) =

= 920 * 1.5 * (45 – 20) + 4200 * 0.8 * (45 – 20) = 34500 + 84000 = 118500 J.

Qdata = s (water) * m (added water) * (t1 – t2) =

4200 * m (added water) * (100 – 45) = 231000 * m (added water).

Qdata = Qreceived;

231000 * m (added water) = 118500;

m (added water) = 0.513 kg = 513 g.

The density of water is 1 g / ml, so the volume of boiling water to be added = 513 ml.

Answer: 513 ml.