What is the final concentration if a 50.0 mL sample of a 15% H2SO4 solution is added to water to give a final volume of 250 mL? 1.5% H2SO4 solution
25% H2SO4 solution
3% H2SO4 solution

The teacher is mostly talking about the distillation of a mixture

Answeramino acids;

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.