An amount of molten silver at its melting point (962°C) is added to 1.00 kg of water at 20.0°C. The final temp is 75.8°C. Find the mass of the silver.

Answer 1

Find q for water:

q=mcΔt

q=(1000g)(4.18 J/gC)(75.8C-20.0C)

q=233244 J

|+q_water|=|-q_silver|

q_silver= -233244 J = -233.244 kJ

Latent Heat of Fusion of Silver is 11.3 kJ/mol (googled this, you need delta H fusion for solid↔liquid)

q=nΔHfus

q=heat in kJ

n=mol

ΔHfus silver= 8.8*10⁴ J/kg= 8.8*10¹ kJ/kg

-233.244=n(-8.8*10¹)

n=2.6505 mol

1 mol Ag=107.87 g/mol

2.6505mol (107.87 g/mol) = 285.9 g Ag