Most single replacement reactions involve one metal replacing another metal in a compound.
For example, sodium and silver are both metals (unlike chlorine), so they could pull the ole switcheroo:
sodium + silver chloride → silver + sodium chloride
Na + AgCl → Ag + NaCl
Unfortunately, not all single replacement reactions will occur (sometimes the ole switcheroo does not take place).
We can use the Activity Series of Metals (seen below) to determine if the lone element is, in fact, reactive enough to take the place of the element in the compound. The higher on the table, the more reactive the metal and the more likely it is to replace another.
Reactivity Trends for the Non-metals
Recall that we learned about reactivity trends for the non-metals (reactivity increases from left to right and from bottom to top).
Predicting Products – Single Replacement Reactions
Just like with synthesis and decomposition reactions, we will usually be given the start of the word equation. We will then finish the word equation and create a balanced equation.
When converting from the word equation to the balanced equation, recall that we have to remember which elements are special dudes. Also, the formulae for compounds are the result of cross-crossing the valences of the elements found within them
TryIts! Use the valences of the elements, the Activity Series of Metals and the non-metal reactivity trends to predict the products:
(a) sodium + magnesium nitrate →
(b) copper + cobalt (II) chloride →
(c) potassium
chloride + fluorine →
TryIts! Answers:
(a) sodium + magnesium nitrate → sodium nitrate + magnesium
2Na + Mg(NO3)2 → 2NaNO3 + Mg
(b) copper + cobalt (II) chloride → NR
(c) potassium chloride + fluorine → potassium fluoride + chlorine
2KCl + F2 → 2KF + Cl2
Homework:
