What type of solution is ethyl alcohol in water?

Which of the following statements is correct?
$(1)$ Molarity is the number of moles of solute in one liter of solution.
$(2)$ The normality and molarity of a sodium carbonate solution are the same.
$(3)$ The number of moles of solute dissolved in $1000 \ g$ of solvent is defined as molality $(m)$.
$(4)$ The ratio of the mole fractions of solute and solvent is equal to the ratio of their respective moles.

What is the mole fraction of water in $10\%$ by weight $(w/w)$ of aqueous urea solution? [Given: Molar mass of $H, O, C$ and $N$ are $1, 16, 12$ and $14 \text{ g mol}^{-1}$ respectively.]

Which of the following methods of expressing concentration does not change with temperature?

What is the molarity of acid in vinegar containing $4.0 \%$ acetic acid by $(w/w)$ and having a density of $1.02 \ g/mL$ (in $M$)?

$A$ compound $H_2X$ with molar weight of $80 \ g \ mol^{-1}$ is dissolved in a solvent having density of $0.4 \ g \ mL^{-1}$. Assuming no change in volume upon dissolution,the molality of a $3.2 \ M$ solution is: