The number of H atoms in 3(NH₄)₂CrO₄ = 24
<h3>Further explanation </h3>
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
Subscripts in the chemical formula indicate the number of atoms
The compound of 3(NH₄)₂CrO₄ ( 3 molecules of (NH₄)₂CrO₄ ) :
Number of H :

32.066 atomic mass units.
You have to switch the elements based in if they're metals/nonmetals. so nonmetals switch with each other and metals switch with each other.
AB + CD ---> AC + BD
Ionic compounds<span> in solution react </span>faster<span> than molecular </span>compounds<span>. This </span>is <span>because </span>Ionic compounds<span> break apart to form free </span>ions. Therefore, there are no bonds<span> to break </span>so<span> the </span><span>reaction is fast</span>