Semester Review Worksheet #2 What is pH a measure of? 1. What is the equation used for finding pH? 2. What is pOH a measure of? 3. What is the equation for finding pOH? 4. What is the equation that relates to pH and pOH? 5. What is the equation that relates [H+] and [OH-]? 6. Complete the following table [H3O+] 1.0 x 10-9 M [OH-] pH pOH Acidic/Basic? 4.1x10-2 M 3.75 5.45 7. How many joules are needed to warm 25.5 grams of water from 14.0oC to 22.5oC? 8. Calculate the number of joules released when 75.0 grams of water are cooled from 100.0oC to 27.5oC. 9. Calculate the heat, in joules, needed to warm 225 grams of water from 88.0oC to its boiling point, 100.0oC. 10. The specific heat of gold is 0.128 J/gCo. How much heat would be needed to warm 250.0 grams of gold from 25.0C to 100.0C? 11. Write the abbreviated electron configurations of the following elements: iridium ________________________________________________ chlorine ________________________________________________ nobelium ________________________________________________ cesium ________________________________________________ magnesium ________________________________________________ 12. The following electron configurations belong to which elements: 1s22s22p63s1 ____________________ 1s22s22p63s23p64s23d104p65s24d6 ____________________ [Kr] 5s24d10 ____________________ [Xe] 6s24f145d106p2 ____________________ [Rn] 7s25f146d4 ____________________ 13. Calculate the frequency of light with wavelength = 2.50 x 10-7m. 14. What is the energy of cell phone radiation with a 1.0 m wavelength? 15. What is the energy (Joules) of Violet light with a frequency = 7.50 x 1014 s-1. 16. One student performed an experiment in which nitrogen and hydrogen gas were mixed together to form ammonia. Equilibrium concentrations of the three species were [NH3] = 0.157 M, [N2] = 0.921 M and [H2] = 0.763 M. 1N2 + 3H2 → 2NH3 What is the equilibrium expression for this reaction? Calculate the value of the equilibrium constant 17. Sodium-24 has a half-life of 15 hours. How much sodium-24 will remain in an 18.0 g sample after 60 hours? 18. After 42 days a 2.0 g sample of phosphorus-32 contains only 0.25 g of the isotope. What is the half-life of phosphorus-32? 19. Polonium-214 has a relatively short half-life of 164 seconds. How many seconds would it take for 8.0 g of this isotope to decay to 0.25 g?