What is relative lowering of vapour pressure ?

What is the relative lowering of vapour pressure ? How is it useful in determining the molecular weight of solute ?

The vapour pressure of a pure liquid is 0.043 bar at a certain temperature. When a nonvolatile solute is dissolved into it, the vapour pressure of the solution is found to be 0.041 bar. What is the relative lowering of vapour pressure?

Show that relative lowering of vapour pressure is a colligative property.

Show that relative lowering of vapour pressure is a colligative property.

What is meant by lowering of vapour pressure? How does the relative lowering of vapour pressure depend on the number of moles of solute in a solution?

What do you mean by relative lowering of vapour pressure? Calculate the relative lowering of Vapour pressure of a solution formed by dissolving 50 g of urea (NH_2 CONH_2) in 850g of water.(Given vapour pressure of pure water at 298K= 23.8mm of Hg.)