How many moles of sochum are needed to react with sulfuric acid to produce 3.75 moles of sodium sulfate according to the following (unbalanced) reaction

Na + ___ H2(SO4)—> ___ Na2(SO4) + ___H2

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

Why does his teacher ask him to balance the equation by including the correct coefficient

What is the solubility-product constant of barium sulfate, baso4, if a saturated solution is 1.03 ´ 10-5 m?