c) An aluminum tea kettle with mass 1.10 kg containing 1.80 kg of water is placed on a stove. If no heat is lost to the surroundings, how much heat must be added to raise the temperature from 20o C to 95o C

Respuesta :

Answer:

Q = 640425 J = 640.425 KJ

Explanation:

From the law of conservation of energy:

Heat Addition = Heat Gain of Water + Heat Gain of Aluminum Kettle

[tex]Q = m_wC_w\Delta T_w + m_aC_a\Delta T_a[/tex]

where,

Q = Heat addition required = ?

[tex]m_w[/tex] = mass of water =1.8 kg

[tex]m_a[/tex] = mass of aluminum kettle = 1.1 kg

[tex]C_w[/tex] = specific heat capacity of water = = 4200 J/kg.°C

[tex]C_a[/tex]  = specific heat capacity of aluminum kettle = = 890 J/kg.°C

[tex]\Delta T_w[/tex] = [tex]\Delta T_a[/tex] = change in temperature of water and kettle = 95°C - 20°C = 75°C

Therefore,

[tex]Q = (1.8\ kg)(4200\ J/kg.^oC)(75^oC)+(1.1\ kg)(890\ J/kg.^oC)(75^oC)\\[/tex]

Q = 567000 J + 73425 J

Q = 640425 J = 640.425 KJ