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Introduction Many compounds are formed as a result of reactions that occur in water solutions. These compounds appear to be dry, but when they are heated, large amounts of water are released. The water molecules are part of the crystalline structure and are weakly bonded to the ions or molecules that make up the compound Such compounds are known as hydrates, meaning that they contain water. The solid that remains when the water is removed is referred to as the anhydrous salt, or anhydrate. Hydrate + Heat arrow Anhydrate +H_(2)O Usually, the amount of water present in a hydrate is in a whole number molar ratio to the moles of anhydrate An example of a hydrate is magnesium sulfate. Its formula is MgSO_(4)cdot 7H_(2)O, indicating that seven moles of water are combined with one mole of magnesium sulfate in the crystalline form. In this investigation you will be given an unknown hydrate and asked to percent of water in the compound. From this information, the molar ratio of water to anhydrous salt will be calculated. Finally, the identity of the hydrate will be determined. Pre-Lab Discussion Read the entire laboratory investigation and the relevant pages of your textbook. Then answer the that follow. 1. __ 2. Why do you think it is necessary to heat the evaporating dish before finding its mass? __ __ 3. Why must the evaporating dish be cooled before finding its mass? 4. Why must the mass of the anhydrous salt be measured immediately __ preparation

Pergunta

Introduction Many compounds are formed as a result of reactions that occur in water solutions. These compounds appear to be dry, but when they are heated, large amounts of water are released. The water molecules are part of the crystalline structure and are weakly bonded to the ions or molecules that make up the compound Such compounds are known as hydrates, meaning that they contain water. The solid that remains when the water is removed is referred to as the anhydrous salt, or anhydrate. Hydrate + Heat arrow Anhydrate +H_(2)O Usually, the amount of water present in a hydrate is in a whole number molar ratio to the moles of anhydrate An example of a hydrate is magnesium sulfate. Its formula is MgSO_(4)cdot 7H_(2)O, indicating that seven moles of water are combined with one mole of magnesium sulfate in the crystalline form. In this investigation you will be given an unknown hydrate and asked to percent of water in the compound. From this information, the molar ratio of water to anhydrous salt will be calculated. Finally, the identity of the hydrate will be determined. Pre-Lab Discussion Read the entire laboratory investigation and the relevant pages of your textbook. Then answer the that follow. 1. __ 2. Why do you think it is necessary to heat the evaporating dish before finding its mass? __ __ 3. Why must the evaporating dish be cooled before finding its mass? 4. Why must the mass of the anhydrous salt be measured immediately __ preparation

Introduction Many compounds are formed as a result of reactions that occur in water solutions. These compounds appear to be dry, but when they are heated, large amounts of water are released. The water molecules are part of the crystalline structure and are weakly bonded to the ions or molecules that make up the compound Such compounds are known as hydrates, meaning that they contain water. The solid that remains when the water is removed is referred to as the anhydrous salt, or anhydrate. Hydrate + Heat arrow Anhydrate +H_(2)O Usually, the amount of water present in a hydrate is in a whole number molar ratio to the moles of anhydrate An example of a hydrate is magnesium sulfate. Its formula is MgSO_(4)cdot 7H_(2)O, indicating that seven moles of water are combined with one mole of magnesium sulfate in the crystalline form. In this investigation you will be given an unknown hydrate and asked to percent of water in the compound. From this information, the molar ratio of water to anhydrous salt will be calculated. Finally, the identity of the hydrate will be determined. Pre-Lab Discussion Read the entire laboratory investigation and the relevant pages of your textbook. Then answer the that follow. 1. __ 2. Why do you think it is necessary to heat the evaporating dish before finding its mass? __ __ 3. Why must the evaporating dish be cooled before finding its mass? 4. Why must the mass of the anhydrous salt be measured immediately __ preparation

Solução

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WilmaVeterano · Tutor por 11 anos

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1. A hydrate is a compound that contains water molecules within its crystalline structure. These water molecules are weakly bonded to the ions or molecules that make up the compound. When the hydrate is heated, the water molecules are removed, leaving behind the anhydrous salt.<br /><br />2. It is necessary to heat the evaporating dish before finding its mass because this helps to remove any residual water or moisture that may be present in the dish. By heating the dish, any remaining water will evaporate, leaving the dish at a dry and consistent temperature. This ensures that the mass of the dish is accurate and not influenced by the presence of water.<br /><br />3. The evaporating dish must be cooled before finding its mass because if it is still hot, the heat from the dish can affect the accuracy of the mass measurement. When the dish is cooled, the temperature becomes consistent, and the mass can be measured accurately without any influence from the heat.<br /><br />4. The mass of the anhydrous salt must be measured immediately after preparation because the anhydrous salt is still in a hot and unstable state after the heating process. If the mass is not measured right away, the anhydrous salt may absorb moisture from the air or undergo further reactions, which could affect the accuracy of the mass measurement. By measuring the mass immediately after preparation, the most accurate and reliable result can be obtained.
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