How many moles of molecules are there in $18 \mathrm{g}$ of hydrogen $\left({\mathrm{H}}_2\right)$?

How many moles of molecules are there in $54 \mathrm{g}$ of water?

The reaction between magnesium and oxygen is:

$2\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

Write a word equation for the reaction.

The reaction between magnesium and oxygen is:

$2\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

How many moles of magnesium atoms react with $1$ mole of oxygen molecules?

The reaction between magnesium and oxygen is:

$2\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

The ${\mathrm{A}}_{\mathrm{r}}$ values are: $\mathrm{Mg}=24, \mathrm{O}=16$. How many grams of oxygen react with: $48 \mathrm{g}$ of magnesium?

The reaction between magnesium and oxygen is:

$2\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)$

The ${\mathrm{A}}_{\mathrm{r}}$ values are: $\mathrm{Mg}=24, \mathrm{O}=16$. How many grams of oxygen react with: $12 \mathrm{g}$ of magnesium?

Copper carbonate breaks down on heating, like this: ${\mathrm{CuCO}}_3\left(\mathrm{s}\right)\to \mathrm{CuO}\left(\mathrm{s}\right) + {\mathrm{CO}}_2\left(\mathrm{g}\right)$

Write a word equation for the reaction.