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).

CaCl₂.3H₂O

We are given;

We are supposed to determine the formula of the hydrate;

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

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

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

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?