A metal block is made from a mixture of 2.4 kg of aluminum 1.6 kg brass and 0.8 kg of copper. The amount of heat required to raise the temperature of this block from 20 C to 80 C is (specific heats of aluminum, brass and copper are 0.216, 0.0917 and 0.0931 cal kg l ° C - respectively)
Answers
The amount of heat required to raise the temperature is 44.376 cal/°C
Explanation:
Mass of Al = 2.4 kg
Mass of brass = 1.6 kg
Mass of copper = 0.8 kg
Initial temperature = 20 °C
Final temperature = 80°C
Amount of heat required to raise the temperature = ?
Specific heat capacity of Al = 0.216 cal/ kg.°C
Specific heat capacity of brass = 0.216 cal/kg.°C
Specific heat capacity of Cu = 0.216 cal/kg°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 80°C - 20°C = 60°C
Q = m₁ + m₂ + m₃
m₁ (Al)= m₁.c. ΔT
m₂( brass)= m₂c. ΔT
m₃(Cu) = m₃c. ΔT
m₁ (Al)= 2.4 kg×0.216 cal/kg.60°C
m₁ (Al) = 31.104 cal/°C
m₂( brass) = m₂c. ΔT
m₂( brass) = 1.6 kg×0.0917 cal/kg.60°C
m₂( brass) = 8.8032 cal/°C
m₃(Cu) = m₃c. ΔT
m₃(Cu) = 0.8 kg×0.0931 cal/kg.60°C
m₃(Cu) = 4.4688 cal/°C
Q = m₁ + m₂ + m₃
Q = 31.104 cal/°C + 8.8032 cal/°C + 4.4688 cal/°C
Q = 44.376 cal/°C