A sample of hydrogen gas (3.2 l) at 3.5 atm and 25 °c was combined with 5.2 l of nitrogen gas at 7.3 atm and 25 °C at constant temperature in a 15.0 l flask. Assuming the initial pressure in the flask was 0.00 atm and the temperature upon mixing was 25 °., What is the total pressure (atm) in the flask?

Answer//the law of conservation of mass.;

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.