In an experiment, potassium chlorate decomposed according to the following chemical equation.
kcio3 → kci + o2
(molar mass of kcio, - 1225 g/mol kci = 74.55 g/mol; o2 = 31.998 g/mol)
if the mass of kcl produced was 180 grams, which of the following calculations can be used to determine the mass of potassium chlorate decomposed?
(180 x 2 x 74.55) + (122.5 x 2) grams
(180 x 3 x 74.55) + (122.5 x 2) grams
o (180 * 2 * 122.5) + (74.55 * 2) grams
1902
122.5) + (74 55 x 2) grams

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the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

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.