Calcium chloride, when dissolved in water, dissociates into its ions according to the following equation CaCl 2 aq → Ca ( 2 + ) aq + 2 Cl - aq Calculate the number of ions obtained from CaCl 2 when 222 g of it is dissolved in water.

1 mole of calcium chloride =111g 222g of CaCl 2 is equivalent to 2 moles of CaCl 2 Since 1 formula unit CaCl 2 gives 3 ions, therefore, 1 mole of CaCl 2 would give 3 moles of ions 2 moles of CaCl 2 would give 3 × 2 = 6 moles of ions. Number of ions = Number of moles of ions × Avogadro number . = 6 × 6 . 022 × 10 23 = 36 . 132 × 10 23 = 3 . 6132 × 10 24 ions.

Calcium chloride, when dissolved in water, dissociates into its ions according to the following equation CaCl 2 aq → Ca ( 2 + ) aq + 2 Cl - aq Calculate the number of ions obtained from CaCl 2 when 222 g of it is dissolved in water.

1 mole of calcium chloride =111g 222g of CaCl 2 is equivalent to 2 moles of CaCl 2 Since 1 formula unit CaCl 2 gives 3 ions, therefore, 1 mole of CaCl 2 would give 3 moles of ions 2 moles of CaCl 2 would give 3 × 2 = 6 moles of ions. Number of ions = Number of moles of ions × Avogadro number . = 6 × 6 . 022 × 10 23 = 36 . 132 × 10 23 = 3 . 6132 × 10 24 ions.

A sample of ethane C 2 H 6 gas has the same mass as 1 . 5 × 10 20 molecules of methane ( CH 4 ). How many C 2 H 6 molecules does the sample of gas contain?.

Number of molecules of methane = 1 . 5 × 10 20 molecules. Mass of one mole of C 2 H 6 = 30 g Mass of one mole of CH 4 = 16 g . 1 mole of a substance contains 6 . 022 × 10 23 molecules. Mass of 6 . 022 × 10 23 molecules of methane = 16 g . Mass of 1 . 5 × 10 20 molecules of methane = 16 × 1 . 5 × 10 20 6 . 022 × 10 23 = 3 . 98 × 10 - 3 30 g of Ethane contains 6 . 022 × 10 23 molecules. 3 . 98 × 10 - 3 g of ethane will contain 6 . 022 × 10 23 × 3 . 98 × 10 - 3 30 = 0 . 8 × 10 20 molecules. = 8 × 10 19 molecules. = 0 . 8 × 10 20 molecules.