Respuesta :
Explanation:
It is known that the relation between heat energy, specific heat and change in temperature is as follows.
q = [tex]m \times C \times \Delta T[/tex]
where, q = heat released or absorbed
m = mass of substance
C = specific heat
[tex]\Delta T[/tex] = change in temperature
It is given that mass is 25.2 g and it is added to 150 ml container so total mass will be (25.2 g + 150 g) = 175.2 g, [tex]T_{1}[/tex] is [tex]20^{o}C[/tex], [tex]T_{2}[/tex] is [tex]8.5^{o}C[/tex], and specific heat of water is 4.184 [tex]J/g ^{o}C[/tex].
Hence, putting the given values into the above formula as follows.
q = [tex]m \times C \times \Delta T[/tex]
= [tex]175.2 g \times 4.184 J/g^{o}C \times (8.5 - 20)^{o}C[/tex]
= [tex]175.2 g \times 4.184 J/g^{o}C \times -11.5^{o}C[/tex]
= -8430 J
As, 1 J = 0.001 kJ. Hence, -8430 J will also be equal to -8.43 kJ. The negative sign indicates that heat is being lost.
Thus, we can conclude that heat (kJ) was lost by the solution (surroundings) is 8.43 kJ.
