Calculate the standard heat of reaction (AHº) for the formation of carbon dioxide according to the following equation.
2C0 (+02(g)→ 2CO2(g)
Heats of Formation:
AHCO(g) = -110.5 kJ/mol
AHt, O2(g) = 0 kJ/mol (free element)
AHt, C02(g) = -393.5 kJ/mol
-566 kJ
-504 kJ
-283 kJ
-787 kJ

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.