Calculate the specific heat capacity of aluminum if 14,200 J of heat is released in cooling a 350.0
galuminum bar from 70°C to 25 °C. Is heat endothermic or exothermic? Why?

Respuesta :

Answer:

                     Specific Heat Capacity  =  0.901 J.g⁻¹.°C⁻¹

                     Heat is Exothermic

Explanation:

                     Specific heat capacity is the amount of heat required to raise the temperature of a given amount of substance by one degree.

Also, Exothermic reactions are those reaction in which the heat is lost from the system to surrounding while, endothermic reactions are those in which the system gains heat from the surroundings.

The equation used for this problem is as follow,

                                                 Q  =  m Cp ΔT   ----- (1)

Where;

           Q  =  Heat  =  14200 J

           m  =  mass  =  350 g

           Cp  =  Specific Heat Capacity  =  ??

           ΔT  =  Change in Temperature  =  70 °C  -  25 °C  =  45 °C

Solving eq. 1 for Cp,

                                Cp  =  Q / m ΔT

Putting values,

                                Cp  =  14200 J / (350 g × 45 °C)

                                Cp  =  0.901 J.g⁻¹.°C⁻¹

As the heat is lost by the metal therefore, the heat is exothermic.