Most popular questions and responses by ChemGeek
  1. Chemistry

    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

    asked on November 4, 2013
  2. Chemistry

    the density of an unknown metal is 2.64 g/cm^3 and its atomic radius is 0.215 nm. It has a face-centered cubic lattice. What is the atomic weight. Answer: 89.4 g/mol how?

    asked on May 15, 2011
  3. Chemistry

    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?

    asked on May 25, 2011
  4. Chemistry

    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

    asked on May 27, 2012
  5. Chemistry

    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

    asked on May 20, 2011
  6. Chemistry

    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) +

    asked on June 1, 2011
  7. Chemistry

    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

    asked on May 15, 2011
  8. Chemistry

    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

    asked on May 18, 2011
  1. Science

    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

    posted on May 27, 2012
  2. Chemistry

    q = mc delta t right?

    posted on May 25, 2011
  3. Chemistry

    I totally agree with anon and rocky...Tony is STUPID

    posted on November 15, 2010