The molality (in $mol \ kg^{-1}$) of $1 \ mol$ of solute in $50 \ g$ of solvent is

How much water should be added to $200 \, cc$ of a semi-normal solution of $NaOH$ to make it exactly deci-normal?

The molecular weight of glucose is $180$. $A$ solution of glucose which contains $18 \ g$ per litre is ........... $molal$.

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

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.

If a solution is $98\% \ H_2SO_4$ by weight and has a density of $1.8 \ g/mL$,its molarity is ....... $M$.