1. Definition of the four laws of thermodynamicsThe first law of thermodynamics states that energy is neither created nor destroyed but it can be transformed. It further explains that in all processes, the sum of energy in the universe remains unchanged. Therefore, although there are constant energy transformations taking place in the universe, the total energy in a closed system stays the same. The second law of thermodynamics states says that the entropy of a closed system, which is not in equilibrium tends to rise with time and reaches the optimum value when at equilibrium. The third law of thermodynamics says that as temperature tends toward the absolute zero, the entropy of any system will tend towards a stable minimum. The Zeroth law of thermodynamics can be defined in the expression, when system A and system B are both in thermal equilibrium with system C, then also system A is in thermal equilibrium with system B; where A, B and C represent different thermodynamic bodies or system. 2) ii) In general, entropy is simply a measure of a system’s disorder.
In thermodynamics, however, entropy is a measure of the amount of energy that is unavailable to do work in a system.
ii) When ice melts into water, the water molecules which had been held together breaks apart and are free to move about. In this state, therefore, water is in liquid form. iii) When ice melts into water, the entropy of water and ice increases while that of the surrounding decreases. 3)The entropy of: 2 NO(g) = 2 * 90.3 KJ/mol = 180.6 KJ/molO2(g) = 0 KJ/molN2O4(g) = 9.2 KJ/moli) ΔS in 2 NO(g) + O2(g) →N2O4(g) = [∑ of S in N2O4(g)] – [∑ of S in 2 NO(g) + O2(g)] = (180.6 KJ/mol) - (9.2 KJ/mol + 0 KJ/mol) = 171.4 KJ/molii) The entropy decreases since three molecules of gas in the reactants reduces to two molecules of gas. iii) The reaction will be spontaneous4)i) absolute Zero in, Kelvin is 0 °KCelsius is -273.15 °CFahrenheit is -459.67 °F Rankine scales is 0 °Rii) The boiling point of water in Kelvin is 373.15 Kiii) if the temperature of a system rises by 30°C during a heating process, the rise in temperature in Kelvins (°K ) = °C + 273.15 = 30°C + 273.15 = 303.15iv) if the temperature of a system rises by 60°F during a heating process, this rise in temperature in, °R = °F + 459.67 = 60°F + 459.67 = 519.67 °R°K = (°F + 459.67) × 5/9 = (60°F + 459.67) * 5/9 = 288.7056 °K°C = (°F − 32) /1.8 = (60°F – 32) / 1.8 = 10 °C5) When a closed system is in equilibrium, then there is no work that is derived. 6) An example of: -i) An equilibrium state is an ideal gas with a distribution function stabilised to a particular Maxwell-Boltzmann distribution. ii) A steady state can be the fluid flowing through a tube such that the flow is constant. iii) A uniform state is Give examples of equilibrium state, steady state and uniform.
(3 marks)7) A rechargeable battery, a household refrigerator, and a radiator represent closed systems since only energy flows in and out but matter does not. 8) The difference between a gas, a liquid and a solid is that molecules in gas molecules are too loose and therefore, its volume and shape is not definite; a liquid has a definite volume but its shape is nor definite; while a solid has both definite volume and shape.