Complete and balance the following equations:

$\mathrm{Cu}+\mathrm{HCl}\to$

Complete and balance the following equation:

$\mathrm{Zn}+{\mathrm{MgSO}}_4\to$

Complete and balance the following equation:

$\mathrm{KI}+{\mathrm{Br}}_2\to$

Complete and balance the following equation:

$\mathrm{Al}+\mathrm{NaCl}\to$

Complete and balance the following equation:

$\mathrm{K}+{\mathrm{Al}}_2{\left({\mathrm{SO}}_4\right)}_3\to$

Complete and balance the following equation:

$\mathrm{Cu}+{\mathrm{AgNO}}_3\to$

Complete and balance the following equation:

$\mathrm{Al}+{\mathrm{H}}_2{\mathrm{SO}}_4\to$

Arrange the following elements in decreasing order of reactivity:

$\mathrm{Cu}, \mathrm{Ag}, \mathrm{Al}, \mathrm{Mg}, \mathrm{Fe}, \mathrm{K}, \mathrm{Zn}, \mathrm{Au}$

Complete and balance the following chemical equation:

$\mathrm{NaCl}+{\mathrm{AgNO}}_3\to \mathrm{\_\_\_\_\_}+ {\mathrm{NaNO}}_3$