What quantity of carbon dioxide is produced when $2 \,mol$ of carbon is burnt in $16 \,g$ of dioxygen (in $\,g$)?

The amount of heat evolved when $500 \text{ cm}^{3}$ of $0.1 \text{ M } HCl$ is mixed with $200 \text{ cm}^{3}$ of $0.2 \text{ M } NaOH$ is (in $\text{ kJ}$)

The mass of $N_2F_4$ produced by the reaction of $2.0 \ mol$ of $NH_3$ and $8.0 \ mol$ of $F_2$ is $0.5 \ mol.$ What is the per cent yield?
$2NH_3 + 5F_2 \to N_2F_4 + 6HF$

How much amount of $Al_2O_3$ will be formed when $5.4 \ g$ of $Al$ reacts with $10 \ g$ of $O_2$? .......... $g$

For the reaction $2Al + 3MnO \xrightarrow{\Delta} Al_2O_3 + 3Mn$; If $108 \ g$ of $Al$ and $213 \ g$ of $MnO$ are heated,then which of the following is incorrect?

$3O_2 + 2N_2 \to 2N_2O_3$
$9 \ mol$ of $O_2$ and $14 \ mol$ of $N_2$ are allowed to react. When $3 \ mol$ of $O_2$ remains unreacted,how many moles of $N_2O_3$ would have been produced?