Determining the Formula of Hydrated Salt Essay Example
INQUIRY- What is the percentage by mass of water in Epson salt?
DISCUSSION- When a crystal forms from water solutions, it takes a certain amount of water as part of the crystalline structures. The water is not covalently bonded to the host molecule or ion. Water is taken up in definite proportion in relation to the mass of the crystalline structure. This water that is trapped inside the hydrated solid structure is called water of crystallization or water of hydration. A salt with associated water of crystallization is known as a hydrate. The formula of a hydrated salt is written as the number of moles of water present in one mole of crystalline structure. Deliquescent materials are substances that absorb water from the atmosphere and eventually become hydrated. These materials, usually salts, tend to have a high affinity for water. During this process, the actual structure of the crystalline changes to incorporate the water molecules. This causes the crystal to change in appearance. In order to calculate the amount of water in the crystal, the weight by difference method was used. The amount of water was calculated by measuring the differences in the mass of the hydrous and anhydrous salt. By using this mass, the percentage of water, the number of moles and the complete formula of the salt were derived.
HYPOTHESIS- If the water is driven off of hydrated magnesium sulfate, then it would be colorless because it is made of Group 2 metals, which do not form colors.
OBJECTIVES-
a) To use the method of “weight by difference” to determine mass quantities.
b) To determine the mass of an anhydrous salt by heating the sample to a constant mass.
c) To convert grams to moles.
d) To determine the percent of water in a hydrate sample.
e) To determine the formula of a hydrated compound.
MATERIALS AND EQUIPMENT-
1) Balance
2) Clay triangle
3) Crucible
4) Crucible tongs
5) Burner
6) Iron ring
7) Ring stand
8) Scoopula
9) Wire gauze
10)
DISCUSSION- When a crystal forms from water solutions, it takes a certain amount of water as part of the crystalline structures. The water is not covalently bonded to the host molecule or ion. Water is taken up in definite proportion in relation to the mass of the crystalline structure. This water that is trapped inside the hydrated solid structure is called water of crystallization or water of hydration. A salt with associated water of crystallization is known as a hydrate. The formula of a hydrated salt is written as the number of moles of water present in one mole of crystalline structure. Deliquescent materials are substances that absorb water from the atmosphere and eventually become hydrated. These materials, usually salts, tend to have a high affinity for water. During this process, the actual structure of the crystalline changes to incorporate the water molecules. This causes the crystal to change in appearance. In order to calculate the amount of water in the crystal, the weight by difference method was used. The amount of water was calculated by measuring the differences in the mass of the hydrous and anhydrous salt. By using this mass, the percentage of water, the number of moles and the complete formula of the salt were derived.
HYPOTHESIS- If the water is driven off of hydrated magnesium sulfate, then it would be colorless because it is made of Group 2 metals, which do not form colors.
OBJECTIVES-
a) To use the method of “weight by difference” to determine mass quantities.
b) To determine the mass of an anhydrous salt by heating the sample to a constant mass.
c) To convert grams to moles.
d) To determine the percent of water in a hydrate sample.
e) To determine the formula of a hydrated compound.
MATERIALS AND EQUIPMENT-
1) Balance
2) Clay triangle
3) Crucible
4) Crucible tongs
5) Burner
6) Iron ring
7) Ring stand
8) Scoopula
9) Wire gauze
10)