Question

When 2.246 grams of a calcium chloride hydrate was heated, 0.728 grams of water were
released. Determine the formula of the hydrate (Hint: take the same approach as for the
copper(II) sulfate hydrate).

Answer 1

CaCl₂ · 3 H₂O is the formula of the calcium chloride hydrate.

Explanation:

The formula for the hydrate is CaCl₂ · xH₂O.

To find the number (x) of water molecules in the hydrate, we use the following algorithm.

First we need the molecular weight of the hydrate.

molecular weight of CaCl₂ · xH₂O = 111 + 18 g/mole

Knowing this we devise the next reasoning:

if in         111 + 18x g of CaCl₂ · xH₂O there are 18x g of H₂O

then in   2.246 g of CaCl₂ · xH₂O there are 0.728 g of H₂O

111 + 18x  = (2.246 × 18x) / 0.728

111 + 18x  = 55.53 x

111 = 37.53x

x = 111 / 37.53

x = 2.95 ≈ 3

The formula for the calcium chloride hydrate is:

CaCl₂ · 3 H₂O

Learn more about:

hydrates

https://brainly.com/question/13450632

https://brainly.com/question/919417

#learnwithBrainly

Answer 2

Answer:

CaCl₂.3H₂O

Explanation:

We are given;

• Mass of calcium chloride hydrate as 2.246 grams
• Mass of water of Crystallization as 0.728 grams

We are supposed to determine the formula of the hydrate;

• We are going to use the following steps.

Step 1: Determine the number of anhydrous salt

Mass of anhydrous salt = Mass of the hydrate - mass of the water of crystallization

Mass of anhydrous CaCl₂ = 2.246 g - 0.728 g

                                          = 1.518 g

Step 2: Calculate the number of moles of Anhydrous salt and water of crystallization.

Moles = Mass ÷ Molar mass

Moles of anhydrous salt

Molar mass of anhydrous CaCl₂ = 110.98 g/mol

Moles of CaCl₂ = 1.518 g ÷ 110.98 g/mol

                         = 0.0137 moles

Moles of water

Molar mass of water = 18.02 g/mol

Moles of water = 0.728 g ÷ 18.02 g/mol

                        = 0.0404 moles

Step 3: Calculate the simplest whole number ratio of anhydrous salt to water.

CaCl₂ : H₂O

0.0137 moles : 0.0404 moles

0.0137/0.0137  : 0.0404/0.0137

                      1 : 2.94

                      1 :  3

We get; CaCl₂.3H₂O

Therefore; the formula of the hydrate is CaCl₂.3H₂O