What is the specific heat capacity of an unknown metal if 55.00 g of the metal initially at 90°C is placed in 75mL of water with an initial temperature of 25°C and the final temperature of the system is 35°C?

Respuesta :

Answer:

The specific heat capacity of the unknown metal is 1.04 J/g°C.

Explanation:

Let the specific heat capacity of the unknown metal be [tex]x[/tex].

Given:

Mass of the metal is, [tex]m=55\ g[/tex]

Initial temperature of the metal is, [tex]T_i=90\ \°C[/tex]

Volume of water is, [tex]V=75\ ml[/tex]

Specific heat capacity of water is, [tex]c_w=4.186\ J/g\°C[/tex]

Initial temperature of water is, [tex]T_{wi}=25\ \°C[/tex]

Final temperature of the system is, [tex]T=35\ \°C[/tex]

We know that density of water is equal to 1 g/ml.

Mass is given as the product of density and volume.

Therefore, mass of water is given as:

[tex]m_w=1\times 75=75\ g[/tex]

Now, fall of temperature of the unknown metal is given as:

[tex]\Delta T_m=T_i-T=90-35=55\ \°C[/tex]

Rise of temperature of water is given as:

[tex]\Delta T_w=T-T_{wi}=35-25=10\ \°C[/tex]

Now, as per conservation of energy,

Heat lost by metal = Heat gained by water

⇒ [tex]mx\Delta T_m=m_wc_w\Delta T_w[/tex]

Plug in all the given values and solve for [tex]x[/tex]. This gives,

[tex]55\times x\times 55=75\times 4.186\times 10\\3025x=3139.5\\x=\frac{3139.5}{3025}=1.04\ J/g\°C[/tex]

Therefore, the specific heat capacity of the unknown metal is 1.04 J/g°C.