6 A pure gold ring and pure silver ring have a total mass of

6- A pure gold ring and pure silver ring have a total mass of 15.6 g . The two rings are heated to 75.7 degre celcius and dropped into a 13.3 mL of water at 22.8 degre celcius . When equilibrium is reached, the temperature of the water is 25.3 degre celcius .<?xml:namespace prefix = o ns = \"urn:schemas-microsoft-com:office:office\" />

a)     What is the mass of gold ring? (Assume a density of 0.998 g/mL for water.)

b)    What is the mass of silver ring? (Assume a density of 0.998 g/ml for water.)

Solution

Answer
start with this...
let Z = mass gold ring
16.0g - Z = mass silver ring

then...
heat lost by gold ring + heat lost by silver ring = heat gained by water

so...
(m Cp dT) Au + (m Cp dT) Ag = (m Cp dT) H2O

where..
m Au = Z
Cp Au = 25.418 J/mole