Find mass of unknown metal

Question

What mass of an unknown metal is required to raise the temperature of water from 25°C to 30°C if the heat released is 2730J and the specific heat of the metal is 4.71J/g°C?

Answer 1

Even with the correction provided by your teacher, there is an inconsistency in the problem statement:

 

"What mass of an unknown metal is required to raise the temperature of metal from 25°C to 30°C if the heat released is 2730J and the specific heat of the metal is 4.71J/g°C?"

 

If the temperature of the metal is being raised, then it is absorbing heat, hot releasing heat.  I will work the problem as if you meant to say it is absorbing heat.  

 

Q = mcΔT

 

m = Q/(cΔT)

 

Q = 2730 J

c = 4.71 J/(g°C)

ΔT = 30°C - 25°C = 5°C

 

m = (2730 J) / {[4.71 J/(g°C)] (5°C)} ≅ 116 g

Answer 2

Mass = Density x Volume so I would multiply to get the answer in g.