The theoretical yield of a reaction is the amount of product obtained if the limiting reactant is completely converted to product. Consider the reaction:
P2O5(s) + 3 H2O(l) → 2 H3PO4(aq)

If 16.62 g P2O5 is mixed with 19.90 g H2O, calculate the theoretical yield (g) of H3PO4 produced by the reaction.
(The answer needs to be in g)

We first assume that this gas is an ideal gas where it follows the ideal gas equation. the said equation is expressed as: pv = nrt. from this equation, we can predict the changes in the pressure, volume and temperature. if the volume and the temperature of this gas is doubled, then the pressure still stays the same.

Vander waals forces are inter molecular bonds that exist within molecules of the same substance. a water molecule is made up of oxygen and hydrogen atoms which share electrons between each other. the vander waals forces are forces that exist between multitude of different  molecules of water. dipole dipole forces is the type of vander waals force that exist in water. the oxygen atom which is more electronegative pulls the shared electron closer to itself thus generating a partial negative charge while the hydrogen acquire a partial positive charge. these two different charges causes attraction to occur in water molecules.