Formula of a Hydrate
Title: Formula of a Hydrate.
Objective: Determining the percentage of water and the chemical formula of a hydrate.
Background: Water has a polar structure and it has positively and negatively charged parts within each molecule. This gives it a strong attraction toward ions. The ions in some salts attract and form strong bonds with water molecules. These salts, when they have absorbed water, are called hydrates. Anhydrous salts are salts that can form hydrates but which have had all the water driven off, usually by heat. Hydrated salts are characterized by the number of moles of water molecules per mole of salt.
Sample Calculations:
Mass of hydrate= 35.232g - 32.005g =3.227g
Mass of anhydrous salt= 33.583g - 32.005g =1.581g
Mass of water liberated= 35.232g – 33.586g =1.646g
Mass of h2O in hydrate= 1.646g/3.227g X 100 = 51%
% anhydrous salt in hydrate= 1.581g/3.227g X 100 = 49%
Moles of anhydrous salt in 100g hydrate= 49% X 1mol/120.38= 0.407moles
Moles of water in 100g of hydrate= 51% X 1mol/18.02= 2.83moles
Moles of water per mole of anhydrous salt= 2.83moles/0.407moles= 6.95moles
Average Moles of water per mole of anhydrous salt= 6.95mol / 6.91mol= 6.93mol
Results: According to our results anhydrous salt magnesium has a formula hydrate of MgSO4 + 7H2O. The average moles of water per mole of anhydrous salt obtained: 6.93 moles. This was the average between trial 1 and trial 2. Even though our samples were not measures exactly even we obtained the same results for trail 1 and 2 for the percent of water in the hydrate =51% and percent of anhydrous salt in the hydrate =49%. The mass of hydrate in trial 1 =3.227g and trial 2 =1.973g. The mass of anhydrous salt trial 1 =1.581g and trial 2 =0.972g. Mass of water liberated trial 1 =1.646g and trial 2 =1.001g. Moles of anhydrous salt in 100g of hydrate trial 1 =0.407moles and trial 2 =0.807 moles. Moles of water in 100g of hydrate trial 1 =2.83 moles and trial =2 5.58 moles. Moles of
Objective: Determining the percentage of water and the chemical formula of a hydrate.
Background: Water has a polar structure and it has positively and negatively charged parts within each molecule. This gives it a strong attraction toward ions. The ions in some salts attract and form strong bonds with water molecules. These salts, when they have absorbed water, are called hydrates. Anhydrous salts are salts that can form hydrates but which have had all the water driven off, usually by heat. Hydrated salts are characterized by the number of moles of water molecules per mole of salt.
Sample Calculations:
Mass of hydrate= 35.232g - 32.005g =3.227g
Mass of anhydrous salt= 33.583g - 32.005g =1.581g
Mass of water liberated= 35.232g – 33.586g =1.646g
Mass of h2O in hydrate= 1.646g/3.227g X 100 = 51%
% anhydrous salt in hydrate= 1.581g/3.227g X 100 = 49%
Moles of anhydrous salt in 100g hydrate= 49% X 1mol/120.38= 0.407moles
Moles of water in 100g of hydrate= 51% X 1mol/18.02= 2.83moles
Moles of water per mole of anhydrous salt= 2.83moles/0.407moles= 6.95moles
Average Moles of water per mole of anhydrous salt= 6.95mol / 6.91mol= 6.93mol
Results: According to our results anhydrous salt magnesium has a formula hydrate of MgSO4 + 7H2O. The average moles of water per mole of anhydrous salt obtained: 6.93 moles. This was the average between trial 1 and trial 2. Even though our samples were not measures exactly even we obtained the same results for trail 1 and 2 for the percent of water in the hydrate =51% and percent of anhydrous salt in the hydrate =49%. The mass of hydrate in trial 1 =3.227g and trial 2 =1.973g. The mass of anhydrous salt trial 1 =1.581g and trial 2 =0.972g. Mass of water liberated trial 1 =1.646g and trial 2 =1.001g. Moles of anhydrous salt in 100g of hydrate trial 1 =0.407moles and trial 2 =0.807 moles. Moles of water in 100g of hydrate trial 1 =2.83 moles and trial =2 5.58 moles. Moles of