Question

One mole of carbon (12.0 g) in the form of crystalline graphite is burned at 25◦C and 1.000 atm pressure to form CO2(g). All of the heat produced is used to heat a 5100 g bath of liquid water, originally at 25◦C. What is the final temperature of the water bath? The heat of formation of CO2(g) is −393.5 kJ/mol and the specific heat of water is 4.18 J/g/◦C. Answer in units of ◦C

Answer 1

Answer:

T₂ = 43.46 °C  

Explanation:

Given that:

The heat of the formation of carbon dioxide = - 393.5 kJ/mol (Negative sign suggests heat loss)

It means that energy released when 1 mole of carbon undergoes combustion = 393.5 kJ = 393500 J

Heat gain by water = Heat lost by the reaction

Thus,    

$m_{water}\times C_{water}\times \Delta T=Q$

For water:  

Mass of water  = 5100 g

Specific heat of water = 4.18 J/g°C  

T₁ = 25 °C  

T₂ = ?

Q = 393500 J

So,

$5100\times 4.18\times (T_2-25)=393500$  

T₂ = 43.46 °C