8. mathrm(Ca)(mathrm(OH))_(2)+?=mathrm(CaCl)_(2)+ ?

To balance the chemical equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation.<br /><br />Given equation: \( \mathrm{Ca}(\mathrm{OH})_{2}+?=\mathrm{CaCl}_{2}+ \)?<br /><br />Step 1: Identify the number of atoms of each element in the reactants and products.<br />- In \( \mathrm{Ca}(\mathrm{OH})_{2} \), there is 1 calcium atom, 2 oxygen atoms, and 2 hydrogen atoms.<br />- In \( \mathrm{CaCl}_{2} \), there is 1 calcium atom and 2 chlorine atoms.<br /><br />Step 2: Balance the calcium atoms.<br />- There is 1 calcium atom on both sides, so calcium is already balanced.<br /><br />Step 3: Balance the chlorine atoms.<br />- There are 2 chlorine atoms in \( \mathrm{CaCl}_{2} \), so we need 2 chlorine atoms on the reactant side.<br />- To get 2 chlorine atoms, we need 2 molecules of \( \mathrm{Cl}_{2} \).<br /><br />Step 4: Balance the oxygen and hydrogen atoms.<br />- There are 2 oxygen atoms and 2 hydrogen atoms in \( \mathrm{Ca}(\mathrm{OH})_{2} \).<br />- To balance the oxygen and hydrogen atoms, we need 2 molecules of \( \mathrm{H}_{2}\mathrm{O} \) on the product side.<br /><br />The balanced chemical equation is:<br />\( \mathrm{Ca}(\mathrm{OH})_{2} + 2\mathrm{Cl}_{2} \rightarrow \mathrm{CaCl}_{2} + 2\mathrm{H}_{2}\mathrm{O} \)<br /><br />Therefore, the missing reactant is \( 2\mathrm{Cl}_{2} \) and the missing product is \( 2\mathrm{H}_{2}\mathrm{O} \).