$A$ litre of seawater (which weighs $1030 \ g$) contains $6 \times 10^{-3} \ g$ of dissolved oxygen. The concentration of dissolved oxygen in $ppm$ is:

An aqueous solution of alcohol contains $18 \ g$ of water and $414 \ g$ of ethyl alcohol. The mole fraction of water is

The mole fraction of a solute in a $100$ molal aqueous solution is $.......... \times 10^{-2}$ (Round off to the nearest integer). [Given: Atomic masses: $H = 1.0 \ u$,$O = 16.0 \ u$]

How many grams of $NaOH$ must be dissolved in $500 \, g$ of solution to obtain a $10 \% \, w/w$ concentration?

Sea water,which can be considered as a $6 \ M$ solution of $NaCl$,has a density of $2 \ g \ mL^{-1}$. The concentration of dissolved oxygen $(O_2)$ in sea water is $5.8 \ ppm$. Then the concentration of dissolved oxygen $(O_2)$ in sea water is $x \times 10^{-4} \ m$. $x = ............$ $(Nearest \ integer)$
Given: Molar mass of $NaCl$ is $58.5 \ g \ mol^{-1}$. Molar mass of $O_2$ is $32 \ g \ mol^{-1}$.

Calculate the mole fraction of $C_2H_6O_2$ (ethylene glycol) in an aqueous solution containing $28 \%$ by mass of $C_2H_6O_2$.