Thermochemical Equations
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TIME REMARINO
59:12
Butane (C4H10(9), AH = -1256 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2. Hy = -393 5 kJ/mol ) and water
(H20, AH = -241.82 kJ/mol) according to the equation below
2C4H10 (9) +1302(g) → 8C02(g) + 10H20(9)
What is the enthalpy of combustion (per mole) of C4H10 (9)?
Use AH gen (He products) - (AHt reactants)
-2.657.5 kJ/mol
-5315.0 kJ/mol
-509.7 kJ/mol
-254.8 kJ/mol

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.