Posts by ChemGeek
Total # Posts: 11
The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process, 2 Cu2O + O2 --> 4CuO The change in enthalpy upon reaction of 75.30 g of Cu2O(s) is -76.83 kJ. Calculate the work, w, and energy change, ΔUrxn, when 75.30 g of Cu2O(s) is ...
November 4, 2013
I am unsure of how to approach this question, any help would be greatly appreciated! "2.085g of PCl5 were heated to 250°C in a 500mL vessel: PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) Calculate the initial concentration of PCl5. At equilibrium the concentration of the ...
May 27, 2012
1) Another promiment scientist* 2) as if such devices exist, or will in the very near future.* 3) people should focus on the current practices of science and technology, there is a need for careful oversight upon current problems and practices, rather than imagining possible ...
May 27, 2012
If 200 mL of 3.70 M aqueous Ba(OH)2 and 980 mL of 0.837 M aqueous HClO4 are reacted stoichiometrically according to the balanced equation, how many milliliters of 3.70 M aqueous Ba(OH)2 remain? Round your answer to 3 significant figures. Ba(OH)2(aq) + 2HClO4(aq) → Ba(...
June 1, 2011
Calculate the heat change (q) in kJ for each reaction. Assume the density of the acid solutions is 1.00 g/mL and the heat capacity is 4.184 J/g*°C. i have the Ti and Tf..what equation do i use?
May 25, 2011
Calculate the enthalpy (ΔHo) of reaction (kJ) for the equation as written. If the answer is negative, enter the sign and then the magnitude. 2 HCOOH(l) + O2(g) → 2 CO2(g) + 2 H2O(l) . ΔHof (kJ/mol) HCOOH(l) -409 O2(g) 0 CO2(g) -393.5 H2O(l) -285.83 the answer ...
May 20, 2011
In chem lab we did an experiment with two rods, one that was martensite (one that made a thud sound) and the other austenite (one that made a ping sound). We put both of the rods in N2 and another time we put it in boiling water. Each time the rod would make an opposite sound ...
May 18, 2011
When 0.689 g of Ca metal is added to 200.0 mL of 0.500 M HCl(aq), a temperature increase of 11.2C is observed. Assume the solution's final volume is 200.0 mL, the density is 1.00 g/mL, and the heat capacity is 4.184 J/gC. (Note: Pay attention to significant figures. Do not...
May 15, 2011