Foam cup a has 36 ml of water that contains 2 moles of hcl at 20 degrees celsius. foam cup b has 36 ml of water that contains 2 moles of naoh at 20 degrees celsius. the contents of foam cup a are added to foam cup b and a chemical reaction occurs. the final temperature of the contents of cup b is 31 degrees celsius. i need to calculate the enthalpy change of the reaction. the density of both solutions is 1 g/ml.

What volume of a 2.00 m stock solution of naoh is needed to prepare 150. ml of 0.40 m solution?

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

In the particles are arranged in a regular, repeating pattern. a)a crystalline liquid b)a crystalline solid c)all gases d)all solids