How many moles of $NaOH$ are present in $27 \, mL$ of $0.15 \, M \, NaOH$?

The density of a gas at $STP$ is $2.86 \, g \, L^{-1}$. Which of the following is the gas?

For per gram of reactant,the maximum quantity of $N_2$ gas is produced in which of the following thermal decomposition reactions? (Given: Atomic wt. : $Cr = 52 \ u, Ba = 137 \ u$).

If $10$ volumes of dihydrogen gas react with $5$ volumes of dioxygen gas, how many volumes of water vapour would be produced?

How many moles of ferric alum $(NH_4)_2SO_4 \cdot Fe_2(SO_4)_3 \cdot 24H_2O$ can be made from a sample of $Fe$ containing $0.0056 \ g$ of it?

$SO_{2}Cl_{2}$ on reaction with excess of water results in an acidic mixture: $SO_{2}Cl_{2} + 2H_{2}O \rightarrow H_{2}SO_{4} + 2HCl$. If $16 \, moles$ of $NaOH$ is required for the complete neutralization of the resultant acidic mixture,calculate the number of moles of $SO_{2}Cl_{2}$ used.