chemistry - science (dr. bob222)

Most popular questions
  1. Chemistry - Science (Dr. Bob222)

    Ammonium metavanadate reacts with sulfur dioxide in acidic solution as follows (hydrogen ions and H2O omitted): xVO3^–^ + ySO2 → xVO^2+^ + ySO4^2–^ What is the ratio of x : y? A. 1 : 1 B. 1 : 2 C. 2 : 1 D. 1 : 3 E. 3 : 1

    asked by Ana on May 3, 2014
  2. Chemistry - Science (Dr. Bob222)

    The following reaction has a positive value of ΔG°. 2H2O(g) → 2H2(g) + O2(g) Which of the following statements must be true? A. The reaction is slow. B. The reaction will not occur. That is, when H2O(g) is introduced into a flask, no O2 or H2 will form

    asked by Ana on May 7, 2014
  3. Chemistry - Science (Dr. Bob222)

    How many mmol ( millimoles) of HCl must be added to 130.0 mL of a 0.40M solution of methyl amine (pKb = 3.36) to give a buffer having a pH of 11.59? Thank you for your help!

    asked by Ana on May 6, 2014
  4. Chemistry - Science (Dr. Bob222)

    Liquid chloroform (CHCl3) is placed in a closed container and allowed to equilibrate with chloroform vapor. With the temperature held constant, additional chloroform is introduced into the system, and the vapor-liquid equilibrium is reestablished.

    asked by Ana on May 10, 2014
  5. Chemistry - Science (Dr. Bob222)

    Hydrazine is used as a rocket fuel because its reaction with oxygen is extremely exothermic: N2H4(liquid) + O2(g)  N2(g) + 2H2O(liquid) ΔH(reaction) = -615 kJ mol-1 What is the enthalpy of this reaction if water were produced in the gaseous rather than

    asked by Ana on May 8, 2014
  6. Chemistry - Science (Dr. Bob222)

    Ammonia is a weak base with a Kb of 1.8 x 10-5. A 100.0 mL sample of 0.13 M aqueous solution of ammonia (NH3) is mixed with 87 mL of 0.15 M solution of the strong acid HCl, calculate the pH of the final solution. A) 2.9 B) 11.1 C) 8.8 D) 5.2 E) None of the

    asked by Ana on May 6, 2014
  7. Chemistry - Science (Dr. Bob222)

    Use the following information to answer this question: Cu+(aq) + e- → Cu(s) E° = 0.521V Cu2+ (aq) + e- → Cu+ (aq) E° = 0.153 V. Given these half cell reactions, an aqueous solution of Cu+ ion in the absence of O2(g) : A. will be thermodynamically

    asked by Ana on May 3, 2014
  8. Chemistry - Science (Dr. Bob222)

    Nitrogen gas has values of Cv and Cp of 20.8 and 29.1 J K-1 mol-1, respectively. When a certain amount of nitrogen is heated at constant pressure, what fraction of the heat Q is used to increase the internal energy of the gas, and how is the remaining

    asked by Ana on May 8, 2014
  9. Chemistry - Science (Dr. Bob222)

    Posted by Ana on Saturday, May 3, 2014 at 11:23am. A zinc-copper battery is constructed as follows (standard reduction potentials given below): Zn | Zn2+ (0.10 M) || Cu2+ (2.50 M) | Cu Zn2+ + 2 e- → Zn(s) Eº = -0.76 V Cu2+ + 2 e- → Cu(s) Eº = 0.34 V

    asked by Ana on May 5, 2014
  10. Chemistry - Science (Dr. Bob222)

    Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (°C) [A2]·s–1 1 0.10 100 1.2 x 10–3 2 0.20 200 4.8 x 10–3 3 0.15 ?

    asked by Ana on April 16, 2014
  11. Chemistry - Science (Dr. Bob222)

    A student wanted to determine the amount of copper in a sample of copper ore. The student dissolved a 2.500 ± 0.001 g piece of copper ore in about 75 mL of nitric acid; then, a complexing agent was added. The student transferred this solution to a

    asked by Anonymous on March 25, 2014
  12. Chemistry - Science (Dr. Bob222)

    Consider reaction below: 50H3O^+(aq) + 7Cr2O7^2-(aq) +3I_2(aq) --> 6IO_4^-(aq) + 14Cr^3+(aq) + 75H2O (l) How many electrons are transferred in this reaction?

    asked by Adrik on April 14, 2014
  13. Chemistry - Science (Dr. Bob222)

    Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (°C) [A2]·s–1 1 0.10 100 1.2 x 10–3 2 0.20 200 4.8 x 10–3 3 0.15 ?

    asked by Ana on April 16, 2014
  14. Chemistry - Science (Dr. Bob222)

    At 25 degree C, a student adds 0.400 g of solid phosphoric acid to a beaker containing 500.0ml of water. After the solid is completely dissolved the student adds 20.0ml of a 0.995M sodium hydroxide. What is the pOH of the solution in the beaker?

    asked by Adrik on April 13, 2014