Answer: 32 kcal
Explanation:
[tex]Q= m\times c\times \Delta T[/tex]
Q= heat gained or lost
m= mass of the substance = 874.3 g
c = heat capacity of water = 1 cal/g ° C
[tex]\Delta T={\text{Change in temperature}}=(84.81-48.20)^oC=36.61^0C[/tex]
[tex]Q=874.3g\times 1cal/g^oC\times 36.61^oC[/tex]
Q= 32008.1cal=32..0kcal (1kcal=100cal)
Thus heat lost by 874.3 g of iron is = 32 kcal
Heat lost is represented as a negative sign.