# Why don't bromide ions react with methoxide ions?

May 31, 2016

There are several reasons:

#### Explanation:

There are several reasons:

1. The two species repel each other.

$\text{CH"_3"O"^"-}$ has a negative charge — it is not neutral.

Hence, $\text{Br"^"-}$ and $\text{CH"_3"O"^"-}$ will repel each other.

2. $\text{Br"^"-}$ is an extremely weak base.

HBr is a very strong acid, so its conjugate base $\text{Br"^"-}$ is an extremely weak base.

$\text{Br"^"-}$ has no tendency to remove ${\text{H}}^{+}$ from anything.

3. The product of the attack would be quite unstable.

$\text{Br"^"-" + "CH"_3"O"^"-" → "HBr " + "H" stackrel("-")("C")"O"^"-}$

The repulsion between negative charges on adjacent atoms makes the product a high-energy species.