91影视

• The mass of the metal = 217 g
• The heat absorbed by the metal = 1.43 kJ = 1430 J
• The increase in the temperature of the metal = 24.5 掳C to 39.1 掳C

The heat required to raise the temperature of a substance is given by the formula Q = C\( \times \)m\( \times \)鈭員, where 鈥淐鈥� is the specific heat of the substance, 鈥渕鈥� is the mass of the substance, and 鈥溾垎T鈥� is the change in the temperature of the substance.

Substitute the known values as shown below.

\(\begin{array}{*{20}{l}}{{\rm{1430 J\; = c\;x\;217g x }}\left( {{\rm{ 39}}{\rm{.1^\circ C -- 24}}{\rm{.5 ^\circ C}}} \right)}\\{{\rm{ c\;\; = }}\frac{{{\rm{1430 J}}}}{{{\rm{217 g }} \times {\rm{ }}\left( {{\rm{ 39}}{\rm{.1^\circ C -- 24}}{\rm{.5\;^\circ C}}} \right)}}}\\{{\rm{\; = \;}}\frac{{{\rm{1430J}}}}{{{\rm{217g x 14}}{\rm{.6 ^\circ C}}}}}\\{{\rm{ = }}\frac{{{\rm{1430 J}}}}{{{\rm{3168}}{\rm{.2 g ^\circ C}}}}}\\{{\rm{ = 0}}{\rm{.4513 J/ g^\circ C}}}\end{array}\)

The specific heat value of 0.4513 J matches with the specific heat value of the metal, iron. So, the unknown metal may most likely be iron.