When $1.80 \ g$ of glucose is dissolved in $90 \ g$ of $H_2O$,the mole fraction of glucose is:

$A$ solution is prepared by adding $2 \ g$ of $X$ to $1 \ mole$ of water. Mass percent of $X$ in the solution is $............. \ \%$

If $1 \ M$ and $2.5 \ L$ $NaOH$ solution is mixed with another $0.5 \ M$ and $3 \ L$ $NaOH$ solution,then the molarity of the resultant solution will be $........ \ M$.

When $120 \ g$ of urea (molar mass $= 60 \ g/mol$) is dissolved in $1000 \ g$ of water,the density of the resulting solution is $1.15 \ g/mL$. The molarity of this solution is ........ $M$.

Which of the following statements is correct regarding the mole fraction of components in a solution?

$A$ solution of $H_2O_2$ used for hair bleaching contains approximately $5.0 \ g$ of $H_2O_2$ per $100 \ mL$ of solution. If the molar mass of $H_2O_2$ is $34 \ g/mol$,what is the molarity of this solution?