- A piece of solid
**lead**weighing**38.9**g at a temperature of**318**°C is placed in**389**g of liquid**lead**at a temperature of**369**°C. After a while, the solid melts and a completely liquid sample remains. Calculate the temperature after thermal equilibrium is reached, assuming no heat loss to the surroundings.

The enthalpy of fusion of solid **lead** is ΔH_{fus} = **4.77** kJ/mol at its melting point of **328** °C, and the molar heat capacities for solid and liquid **lead** are C_{solid} = **26.9** J/mol K and C_{liquid} = **28.6** J/mol K.

9.When a **zirconium** bar of mass m is dropped through a height difference Δh, its potential energy changes by the amount mgΔh, where g is the acceleration of gravity, equal to 9.81 m s^{-2}. Suppose that when the bar hits the ground, all that energy is converted to heat, increasing the temperature of the bar. If the specific heat capacity of the material in the bar is **0.278** J K^{-1} g^{-1}, calculate the height from which the bar must be dropped to increase the temperature of the bar by **2.60** °C.

3.The standard enthalpy change of combustion [to CO_{2}(g) and H_{2}O()] at 25°C of the organic solid **heptadecanoic acid**, **C**_{17}**H**_{34}**O**_{2}(s), is determined to be **-10605.6** kJ mol^{-1}. What is the H_{f}° of **C**_{17}**H**_{34}**O**_{2}(s) based on this value?

Use the following data: H_{f}° H_{2}O () = **-285.83** kJ mol^{-1} ; H_{f}° CO_{2}(g) = **-393.51** kJ mol^{-1}

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1)The temperature after thermal equilibrium is reached =... View the full answer