Engineering Board Exam Reviewer · Chemistry · medium

What is the oxidation number of sulfur in H2SO4?

  1. +4
  2. −2
  3. +2
  4. +6

Answer

D. +6

Solution

2(+1) + S + 4(-2) = 0 S = +6.

More Chemistry questions

  1. What is the standard Gibbs free energy change for the Daniell cell reaction (n = 2, E°cell = 1.10 V)? (F = 96,485 C/mol)
  2. How long must a current of 5 A flow to deposit 10 g of silver from a AgNO₃ solution? (Ag = 108, F = 96,485 C/mol)
  3. How many grams of copper are deposited from a CuSO₄ solution by a current of 2 A flowing for 1 hour? (Cu = 63.5, F = 96,485 C/mol)
  4. What is the standard cell potential of a Daniell cell (Zn | Zn2+ || Cu2+ | Cu)? (E°: Cu2+/Cu = +0.34 V, Zn2+/Zn = -0.76 V)
  5. For a reaction with H = -92.2 kJ and S = -198.7 J/K at 298 K, what is G, and is the reaction spontaneous?
  6. A reaction is spontaneous at all temperatures when:
  7. The standard enthalpy of formation of an element in its standard state is:
  8. Hess's law states that the enthalpy change of a reaction:
  9. Calculate H for CH4 + 2 O2 CO2 + 2 H2O(l), given Hf°: CH4 = -74.8 kJ/mol, CO2 = -393.5 kJ/mol, H2O(l) = -285.8 kJ/mol.
  10. Given C + O2 CO2, H = -393.5 kJ, how much heat is released when 24 g of carbon burns completely? (C = 12)

All Chemistry Reviewer questions