In a chemical reaction,the sum of the formula weight of all reactants is $274 \ u$ and the atom economy is $50 \%$. Calculate the formula weight of the desired product. (in $u$)

Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride. The volume of hydrogen gas produced at $STP$ from the reaction of $11.5 \ g$ of zinc with excess $HCl$ is $.......... \ L$ (Nearest integer) (Given: Molar mass of $Zn$ is $65.4 \ g \ mol^{-1}$ and Molar volume of $H_2$ at $STP = 22.7 \ L$)

$A$ solid mixture weighing $5 \ g$ contains equal number of moles of $Na_2CO_3$ and $NaHCO_3$. This solid mixture was dissolved in $1 \ L$ of water. What is the volume (in $mL$) of $0.1 \ M \ HCl$ required to completely react with this $1 \ L$ mixture solution?

Volume of water needed to mix with $10 \ mL$ of $10 \ N$ $HNO_3$ to get $0.1 \ N$ $HNO_3$ is ........... $mL$.

How much heat change in $kJ$ will occur when $233.0 \, g$ of calcium oxide reacts with sufficient carbon to produce $CaC_2$? The reaction is: $CaO_{(s)} + 3C_{(s)} \to CaC_{2(s)} + CO_{(g)}$; $\Delta H^o = 464.8 \, kJ/mol$.

If the concentration of $SO_4^{2-}$ in an aqueous solution of $Al_2(SO_4)_3$ is $0.27 \ M$,then the concentration of $Al^{3+}$ ions will be ....... $M$.