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9 Ιουλ 2019 · By definition, anhydrous compounds are those without water, including crystalline substances after the water of crystallization is removed.
15 Ιαν 2023 · In chemistry, a salt is an electrically neutral chemical compound consisting of cations and anions connected by an ionic bond. The classic example is table salt or sodium chloride (NaCl), which consists of positively charged sodium ions (Na +) and negatively charged chlorine ions (Cl –).
7 Ιουν 2024 · A compound which doesn’t contain water of crystallisation is called an anhydrous compound. E.g. anhydrous copper (II) sulfate is CuSO 4. A compound can be hydrated to different degrees. E.g. cobalt (II) chloride can be hydrated by six or two water molecules. CoCl 2 ∙ 6H 2 O or CoCl 2 ∙ 2H 2 O.
Formula of a Hydrate (\(\text{Anhydrous Solid}\ce{*}x\ce{H2O}\)) The formula of a hydrate can be determined by dehydrating a known mass of the hydrate, then comparing the masses of the original hydrate and the resulting anhydrous solid.
Relative Formula Mass: the mass of the formula unit of a compound with a giant structure. For example, NaCl has a relative formula mass of 58.44 g mol-1. Relative Molecular Mass (M r): the mass of a simple molecule. Ammonium ion: an ion with the formula NH. 4 +. Carbonate: an ion with the formula CO 3 2-. Hydroxide: an ion with the formula OH-.
We can use difference in the mass between the hydrated and anhydrous compound to calculate the mass of water of crystallisation removed by heating.
What is the formula of the hydrate? Solution: 1) Determine mass of water driven off: 15.67 − 7.58 = 8.09 g of water. 2) Determine moles of MgCO 3 and water: MgCO 3 ---> 7.58 g / 84.313 g/mol = 0.0899 mol H 2 O ---> 8.09 g / 18.015 g/mol = 0.449 mol.
