Question

In naming the compound PCl5, the prefix used with the second element is ____________________.

Answer 1

Answer:

$\boxed {\boxed {\sf Hepta}}$

Explanation:

We are given the formula:

$PCl_5$

This is a molecular formula, because it contains nonmetals.

1. Name the first element

The first element is phosphorous (P). Since this is the first element and there is only one, we don't need a prefix.

• Phosphorous

2. Second element

The second element is chlorine (Cl). It has a subscript of 5, so we must add the prefix of hepta-.

• Phosphorous heptachlorine

Add the ending of -ide.

• Phosphorous heptachloride

The prefix used for the second element is hepta. The compound name is phosphorous heptachloride.