Calcium carbonate standard enthalpy

Q O The standard molar enthalpy of formation of calcium carbonate is -1207.6 kj/mol. Calculate the enthalpy of formation of calcium oxide, given the following equation. 

Calcium carbonate occurs as two different crystalline forms, calcite and aragonite.Both forms occur naturally as minerals seeMineralogj. Calcite is the more stable each Ca + is surrounded by six oxygen atoms from COs ions. Aragonite is a metastable form, and its standard enthalpy of formation is about Skjmol higher than that of calcite. In principle, aragonite should decompose to calcite, but a high... 

The enthalpies of reactions between alkaline-earth cuprates M2CUO3 (M = Ca, Sr) and hydrochloric acid were measured in a hermetic swinging calorimeter at 298.15 K. The M2CUO3 samples were prepared by solid-phase synthesis from calcium or strontium carbonate and copper oxide. The standard enthalpies of formation obtained for the cuprates were discussed and compared with previous experimental and assessed values by Monayenkova and coworkers [102]. 

Calcium carbonate (CaCOs) exists in two polymorphic forms, calcite and aragonite. The standard state enthalpy of calcite is -1207.37kJ/mol, while that of aragonite is —1207.74kJ/mol. The entropies of aragonite and calcite under the same conditions are 88Jmol" K" and 91.7 JmoL K, respectively. What is the stable polymorph at 25°C and 1 atm Is there a temperature above which the other polymorph would be the equilibrium phase If so, what is that T If not, why not ... 

We denote the standard state value of a property by the superscript on the symbol for the property, as in for the standard molar enthalpy of a substance and p for the standard pressure of 1 bar. For example, the standard state of hydrogen gas is the pure gas at 1 bar and the standard state of solid calcium carbonate is the pure solid at 1 bar, with either the calcite or aragonite form specified. The physical state needs to be specified because we can speak of the standard states of the sohd, liquid, and vapor forms of water, for instance, which are the pure sohd, the pure liquid, and the pure vapor, respectively, at 1 bar in each case. The standard states of solutions, which are never pure , need to be treated differently (Section 3.8). 

Calcium carbonate is insoluble in water. Yef it dissolves in an acidic solution. Calculate the standard enthalpy, entropy, and Gibbs free energy change for the reaction between sohd calcium carbonate and hydrochloric acid. What drives the reaction, the enthalpy change, or the entropy change ... 

The standard enthalpy of reaction for the decomposition of calcium carbonate is A H° = 813.5 kJ mol . As temperature increases, does the concentration of calcium carbonate increase, decrease, or remain the same Explain. 

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