Question 10 (10 points) (05.06 HC)
A 3.81-gram sample of NaHCO3 was completely decomposed in an experiment.
2NaHCO3 - Na2CO3 + H2CO3
In this experiment, carbon dioxide and water vapors combine to form H2CO3. After
decomposition, the Na2CO3 had a mass of 2.86 grams.
A. Determine the mass of the H2CO3 produced.
B. Calculate the percentage yield of H2CO3 for the reaction. Show your work or
describe the calculation process in detail.
(10 points)

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

Compare and contrast physical changes with chemical changes.

Which statement best explains the relationship between an area is geography and the temperature of its surface water