In the experiment of finding vapour pressure , will the amount of moles of vapour above the liquid phase affects the rate of condensation ? [means if there is more number of moles then then collisions will be more between molecules and more no of vapour molecules are pushed into the water ]

dear mardana 
yes , you are correct , , 
vapour pressure is besically a phenomenon , it doesnot last long, once you are heating a closed container with water inside it , then obviously condensation process running on constantly , 
so, as more no of molecule gather above the surface of water , obviously collision take place , 
HOPE IT CLEARS 
REGARDS