What is meant by mass percentage $( \% w/w )$?

$200 \ mL$ of a solution contains $5.85 \ g$ dissolved sodium chloride. The concentration of the solution will be .......... $molar$ $(Na = 23; Cl = 35.5)$.

What are the mole fraction of water and the total number of moles in a solution formed by dissolving $1$ mole of urea in $1000 \ g$ of pure water,respectively?

The unit of mole fraction is:

Explain the types of solutions based on the physical states of solute and solvent with suitable examples.

For the solution formed by dissolving a solid in water,choose the correct option regarding the following statements: Statement-$1$: $A$ $1$ molal aqueous glucose solution contains $180 \ g$ of glucose in $1000 \ g$ of water. Statement-$2$: $A$ solution containing $1$ mole of solute in $1000 \ g$ of water is called a $1$ molal solution.