Question

Calculate the formula for the following hydrate composed of 76.9% CaSO3 and 23.1% H2O. CaSO3 • H2O CaSO3 • 2H2O CaSO3 • 3H2O

Answer 1

What is the molar mass of the anhydrous compound? Answer using four significant figures.

Answer if on Edge:

120.15 g/mol

Answer 2

Answer:
`CaSO_3.2H_2O`

Step-by-step explanation:

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of
`CaSO_3` =
`\frac{\text{Given mass}}{\text{Molar mass }}=(76.9g)/(120g/mole)=0.64moles`

Moles of
`H_2O` =
`\frac{\text{Given mass}}{\text{Molar mass}}=(23.1g)/(18g/mole)=1.28moles`

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated.

For
`CaSO_3` =
`(0.64)/(0.64)=1`

For
`H_2O` =
`(1.28)/(0.64)=2`

Step 3: Taking the mole ratio as their subscripts.

The ratio of
`CaSO_3` :
`H_2O` is 1: 2

Hence, the formula for the given compound is
`CaSO_3.2H_2O`