A 135 g sample of H20 at 85°C is cooled. The water loses a total of 15 kJ of energy in the cooling

process. What is the final temperature of the water? The specific heat of water is 4.184 J/g.°C.

A. 112°C

B. 58°C

C. 70°C

D. 84°C

E. 27°C

Respuesta :

Answer:

B. 58°C

Explanation:

Hello,

In this case, the relationship among heat, mass, specific heat and temperature for water is mathematically by:

[tex]Q=mCp\Delta T=mCp(T_2-T_1)[/tex]

In such a way, solving for the final temperature [tex]T_2[/tex] we obtain:

[tex]T_2=T_1+\frac{Q}{mCp}[/tex]

Therefore, we final temperature is computed as follows, considering that the involved heat is negative as it is lost for water:

[tex]T_2=85\°C+\frac{-15kJ*\frac{1000J}{1kJ} }{135g*4.184\frac{J}{g\°C} }\\\\T_2=58\°C[/tex]

Thereby, answer is B. 58°C .

Regards.

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