What is volume??? is science form?

"Volume pertains to the three-dimensional space that is occupied by an object (i.e. solid, liquid, gas, or plasma). "

"The amount of space occupied by a three-dimensional figure as measured in cubic units (as inches, quarts, or centimeters) : cubic capacity. 2 : the amount of a substance occupying a particular volume."

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"