Calcium carbide reacts with water to produce acetylene gas according to the following equation: CaC2(s) + 2H2O(l)C2H2(g) + Ca(OH)2(aq) The product gas, C2H2, is collected over water at a temperature of 25 °C and a pressure of 749 mm Hg. If the wet C2H2 gas formed occupies a volume of 5.87 L, the number of moles of CaC2 reacted was mol. The vapor pressure of water is 23.8 mm Hg at 25 °C. Submit Answer

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.

B.1 - hydrogren-1 can only mean there is 1 neutron. it's obvious there is 1 proton or else it wouldn't be hydrogen, so they wouldn't put a number after it unless they were indicating the number of neutrons