4. Heat transfer: q = mass x Cs x ΔT and –qreaction = +qsolution
a. A piece of metal with a mass of 8.6 g was heated to 100.0°C and dropped into a coffee cup
calorimeter containing 402.4 g of water at 25.0°C. If the temperature of the water and the
metal at thermal equilibrium is 26.4°C, what is the specific heat of this metal in J/g°C?
b. How much heat energy must be added in order to boil a liter of water (initial temperature of
24.0°C) in a 1.0 kg copper pot? The specific heat capacity of water is 4.184 J/g°C and the
specific heat capacity of copper is 0.385 J/g°C.
c. A 50.0 g piece of iron (Tinitial = 225°C) and a 50.0 g piece of gold (Tinitial = 25.0°C) are
brought into contact with each other. Assuming no heat is lost to the surroundings, calculate the
temperature of the two metals when they reach thermal equilibrium. The specific heat
capacity of iron = 0.449 J/g°C and the specific heat capacity of gold = 0.128 J/g°C.
d. A 100.0 mL sample of 0.300 M NaOH is mixed with a 100.0 mL sample of 0.305 M HNO3 in
a coffee cup calorimeter. If both solutions were initially at 25.0°C and the maximum
temperature of the resulting mixture was 28.5°C. Find the heat of the reaction, qreaction, in
joules and report the molar heat of reaction, ΔHreaction, in kJ/mole. The density of both
solutions is 1.00 g/mL and heat capacity is the same as water: 4.184 J/g°C.