$4.0 \,g$ of $NaOH$ are contained in one decilitre of solution. Its molarity would be ......... $M$.

If $1.5 \, mol$ of oxygen reacts with $Al$ to form $Al_2O_3$,calculate the mass of aluminum used in the reaction in grams.

$A$ cold drink bottle contains $200 \ mL$ liquid in which $CO_2$ is $0.1 \ M$. Considering $CO_2$ as an ideal gas,the volume of the dissolved $CO_2$ at $S.T.P$ is: (in $L$)

Three substances $A$,$B$ and $C$ react to form $E$ and $D$ as shown: $2A + 3B + C \rightarrow 4D + 2E$. If the molar masses of $A, B, C$ and $D$ are $40, 30, 20$ and $15 \ g/mol$ respectively,and $570 \ g$ of a stoichiometric mixture of $A, B$ and $C$ is reacted,the maximum mass of $E$ obtained will be ............ $g$.

If the percentage purity of an impure sample of a compound is given,then the weight of the substance required to prepare its $0.1 \, N$ solution will be:

The weight of sodium carbonate required to prepare $500 \ mL$ of a semi-normal solution is .......... $g$.