The complete combustion of one mole of benzene produces how many grams of carbon dioxide?

The molarity of a $98\%$ by weight solution of $H_2SO_4$ is .......... $M$. The density of the solution at $35^o C$ is $1.84 \ g/cm^3$.

In a metal deficient oxide sample,$M_X Y_2 O_4$ ($M$ and $Y$ are metals),$M$ is present in both $+2$ and $+3$ oxidation states and $Y$ is in $+3$ oxidation state. If the fraction of $M^{2+}$ ions present in $M$ is $\frac{1}{3}$,the value of $X$ is. . . . . . .

When $10 \ mol$ of $SO_2$ and $15 \ mol$ of $O_2$ are mixed and passed over a catalyst,$8 \ mol$ of $SO_3$ is formed. How many moles of $SO_2$ and $O_2$ remain unreacted?

The Molarity $(M)$ of an aqueous solution containing $5.85 \ g$ of $NaCl$ in $500 \ mL$ water is :
(Given : Molar Mass $Na: 23$ and $Cl: 35.5 \ g \ mol^{-1}$ )

To $50 \ mL$ of $0.1 \ N \ Na_2CO_3$ solution,$150 \ mL$ of water is added. What is the molarity of the resultant solution?