When $30 \ mL$ of $H_2$ reacts with $20 \ mL$ of $O_2$ to form water,what is leftover when the reaction ends?

$20 \ mL$ of $0.1 \ M$ $HCl$ is added to $30 \ mL$ of $0.1 \ M$ $NaOH$. To this solution,an extra $50 \ mL$ of water was added. What is the molarity of the final solution formed (in $M$)?

In a $1 \ L$ vessel, $10 \ \text{moles}$ of methane and $50 \ \text{moles}$ of $O_2$ are present. The number of moles of $O_2$, water, and $CO_2$ present in the vessel after the vessel is heated to burn methane completely are respectively:

If $30 \ mL$ of $H_2$ and $20 \ mL$ of $O_2$ react to form water,what is left at the end of the reaction?

$8 \ L$ of $H_2$ and $6 \ L$ of $Cl_2$ react to the maximum extent. Find the final volume of the reaction mixture in $L$. Assume $P$ and $T$ remain constant throughout the process.

In the reaction $2P_2O_5 + 2HNO_3 \to P_4O_{10} + X$,what is the product $X$?