I have questions for a problem about the first law of thermodynamic
Any help? willing to tip !
The detonation of NaN3 (M=65g) allows the deployment of airbags in about 50-150 ms from a minimal frontal collision of 15-30 km/h (9.3-18.6 miles/h)
The volume of the air bag is (V=50L) and it contains 65g of NaN3 (1 mole).
the reaction is NaN3(s) --> 2 Na (s) + 3 N2 (g) : ΔH = -21.7 kJ/mole
Since the reaction of Na (s) may be dangerous with water, the real reaction in the airbags is
10 Na (s) + 2 KNO3 (s) -->K2O (s) + 2 Na2O (s) + N2 (g)
K2O (s) + Na2O3 (s) + 2 SiO2 (s) --> K2O3Si (s) + Na2O3Si (s)
Questions:
what are the signs for the processus of the deployment of the bags from the decomposition of NaN3: q (heat), w (work), ΔH (enthalpy) (explain)
verify that the quantity of energy transfered to the environment from work by the system is about 5 kJ/mole
verify that the quantity of work expansion done by the system through the deployment of the airbags represent less than 25% of the chemical energy available from the thermic decomposition of NaN3
give 3 hypothesis that would balance the total energy of this processus without breaking the first law of thermodynamic