How many litres of $CO_2$ at $STP$ will be formed when $100 \ mL$ of $0.1 \ M \ H_2SO_4$ reacts with excess of $Na_2CO_3$?

Sulfur trioxide is prepared by the following reactions:
$S_{8(s)} + 8O_{2(g)} \to 8SO_{2(g)}$
$2SO_{2(g)} + O_{2(g)} \to 2SO_{3(g)}$
How many grams of $SO_3$ are obtained from $1 \ mol$ of $S_8$?

$5 \, M$ solution of $H_2SO_4$ is diluted from $1 \, L$ to $10 \, L$. What is the normality of the solution in $N$?

Given the ratio of masses of nitrogen and oxygen in a particular gaseous mixture is $4: 1$. Calculate the ratio of the number of their molecules.

At $300 \ K$ and $1 \ \text{atm}$ pressure,$10 \ mL$ of a hydrocarbon required $55 \ mL$ of $O_2$ for complete combustion,and $40 \ mL$ of $CO_2$ is formed. The formula of the hydrocarbon is

The phosphate of a metal has the formula $MHPO_4$. The formula of its chloride would be