10. Phosphoric acid is a triprotic acid and has values of pKa1 = 2.12, pKa2 = 7.21, and pKa3 = 12.38 at 25 ºC. A student conducts a titration where 150 mL of 0.100 M NaOH(aq) is added to 100 mL of a 0.100 M H3PO4(aq) solution. i. Which species are present in large quantities in the solution at equilibrium at this point? ii. What is the pH of the solution?

How does litmus paper indicate an acid?

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false