Answer:
The final temperature is 34,2 ºC when 1,20 g of wood is burned inside the calorimeter.
Explanation:
The heat of combustion of wood which is approximately 16 kJ/g means that 1 g requires 16 kJ of heat so let's calculate about 1,20 g which is the value of wood you have.
1 g ________ 16 kJ
1,20 g ______ 1,20 g x 16 kJ = 19,2 kJ = 19200 J
Now let's apply the calorimetry formula
Q = m . C . ΔT
19200 J = 500 g . 4,186 J/ gºC ( Tfinal - 25ºC)
<em>Look that we don't have the mass of water, instead we have the volume so as you know water density is 1 g/ml, we conclude that in 500 ml, we have 500 g.</em>
On the other hand we convert the 19.2 kJ into J (* 1000) by the units in the value of the specific heat of the water, it is in Joule
19200 J = 500 g . 4,186 J/ gºC ( Tfinal - 25ºC)
19200 J = 2093 J/ºC ( Tfinal - 25ºC)
19200 J = 2093 J/ºC .Tfinal - 52,325 J
19200 J + 52325 J = 2, 093 J/ºC .Tfinal
71525 J = 2093 J/ºC .Tfinal
71525 J /2093 ºC / J = Tfinal = 34,17ºC
