Let's apply the concept of conservation of energy.
∑E = 0
Energy released by alloy + Energy absorbed by water = 0
Energy released by alloy = - Energy absorbed by water
(mass of alloy)(Cp,alloy)(T - T₀) = -(mass of water)(Cp,water)(T - T₀)
where Cp is the specific heat capacity
Substituting the values,
(86 g)(Cp,alloy)(34.3 - 100) = -(90 g)(4.184 J/g·°C)(34.3 - 20.1)
Solving for Cp,alloy,
Cp,alloy = 0.946 J/g·°C
Therefore, the specific heat of the alloy is 0.946 J/g·°C.
