Which correctly describes the relationship between a hydrate, water, and an anhydrous compound?
heating an anhydrous compound forms water and a hydrate.
adding water to an anhydrous compound forms a hydrate.
combining an anhydrous compound and a hydrate produces water.
removing a hydrate from an anhydrous compound produces water

Adding water to an anhydrous compound forms a hydrate.

Explanation:-

Hydrates are compounds formed by compounds which contain water as molecules in their structure. Example:

Anhydrous compounds are those which do not contain molecules of water in their structure. Example:

Thus on heating hydrates lose water to form anhydrous compounds.

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: