# A ionic compound XY contains 0.050 mol of H﻿2O for every 0.00998mol of ionic compound. The generalized formula for the hydrate is.....?

Jun 9, 2018

The formula for the hydrate is $\text{XY"·5"H"_2"O}$.

#### Explanation:

The general formula of the hydrate is $\text{XY"·n"H"_2"O}$.

There are $n$ mol of water for every mole of $\text{XY}$.

n = ("moles of H"_2"O")/"moles of XY" = (0.050 color(red)(cancel(color(black)("mol"))))/("0.009 98" color(red)(cancel(color(black)("mol")))) = 5.01 ≈ 5

$n$ must be an integer, so the formula of the hydrate is $\text{XY"·5"H"_2"O}$.