# What intra/intermolecular forces exist within a hydrate?

## Take the hydrate Na_2S_2O_3•5H_2O. Are there ionic forces between the $N a +$ and the ${S}_{2} {O}_{3}^{2 -}$ and ion-dipole forces between the cation/anions and the water? HELP! (THANKS)

##### 1 Answer
Mar 25, 2017

Here's what I get.

#### Explanation:

The formula for sodium sulfate is shown below.

Here are the strongest intra- and intermolecular forces present in the crystal.

Intramolecular forces

1. Covalent bonds

(a) $\text{S-O}$ bonds in sulfate ion.
(b) $\text{O-H}$ bonds in water

Intermolecular attractions

2. Strong electrostatic attractions

(c) Ion-ion attractions between $\text{Na"^"+}$ and $\text{SO"_4^"2-}$

3. Weaker electrostatic attractions

(d) Ion-dipole attractions between $\text{Na"^"+}$ and $\text{^"δ-""O-H"^"δ+}$ bond dipoles in water

(e) Ion-dipole attractions between $\text{SO"_4^"2-}$ and $\text{^"δ+""H-O"^"δ-}$ bond dipoles in water

(f) Hydrogen bonds between water molecules: "H-"stackrelcolor(blue)(δ^"-")("O")"···"stackrelcolor(blue)(δ^"+")("H")