$2 \ L$ of $0.2 \ M \ H_2SO_4$ is reacted with $2 \ L$ of $0.1 \ M \ NaOH$ solution. The molarity of the resulting product $Na_2SO_4$ in the solution is $X \ mM$. Find the value of $X$. (Nearest integer).

$20 \ mL$ 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 the balanced equation of the following reaction, the ratio of $a / b$ is: $aCaCO_3 + bH_3PO_4 \rightarrow pCa_3(PO_4)_2 + qCO_2 + rH_2O$

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:

The action of steam on heated iron is represented as:

$2 SO_{2(g)} + O_{2(g)} \rightarrow 2 SO_{3(g)}$
The above reaction is carried out in a vessel starting with partial pressures $P_{SO_{2}} = 250 \ mbar$,$P_{O_{2}} = 750 \ mbar$,and $P_{SO_{3}} = 0 \ mbar$. When the reaction is complete,the total pressure in the reaction vessel is $..... \ mbar$. (Round off to the nearest integer).