1. The decomposition of magnesturn carbonate (MgCO3) is an industrially important
reaction asa widely used method for producing magnesium oxide (c.g., appliedas
thermal insulation or in Portland cement)- The calcination temperature (i.c, the
temperature of decomposition) isa crucial control parameter in obtaining a specific
type of MgO product- This "calcination reaction" proceeds as follows:
We seekto know the cquilibrium temperature at which the calcination reaction will
occur under standard conditions (1 bar). To proceed
a Determine at 298 K (and 1 bar).
b. Determine AGTxn at 800 K (and 1 bar).
C Plot (T) between 300-800 K (at 1 bar) with at least 10 points of data
(using a computer spreadsheet is encollraged).
d. Estimate the equilibrium temperature of decomposition of MgCO= under
standard: state conditions (Note the actual temperature of decomposition in
an industrial reactor will tend to be much higher, and will Vary depending on
the intended use of the Mg0 product).
(kJ J mol-1)
7.28 x 10 3
8.79 x 10
2. Silica (SiO2) has numerous crystalline phases, the most common of which is quartz
since itis thermodynatinically stable at ambient conditions. As pressure increases at
recar ambient temperature, quartz transforms into a denser cystalline phase, cocsite,
and eventually transforms into the high-pressure phase, stishovite-
a Estimate the equilibrium transition pressure of the quattz to coesite phase
transition at 298 K (in units of GPa) using the following data:
*Note: use only the information provided. and make reasonable assumptions
to account for the information that is missing.
b. Estimate the equilibrium pressure of the same phase transition at 1000 K
(also in units of GPa).
C. Compare your results to the phase diagram below. Have you made an
accurate estimation of the transition pressures? What additional information
would be useful in achieving higher accuracy?
These solutions may offer step-by-step problem-solving explanations or good writing examples that include modern styles of formatting and construction
of bibliographies out of text citations and references. Students may use these solutions for personal skill-building and practice.
Unethical use is strictly forbidden.