Preview

Formula of a Hydrate

Satisfactory Essays
Open Document
Open Document
484 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
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

You May Also Find These Documents Helpful

  • Good Essays

    Qwerty

    • 535 Words
    • 3 Pages

    In this experiment the hardness of water was checked due to the presence of calcium and magnesium ions. These ions do not pose any…

    • 535 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Although the data did not match the actual empirical formula of a 1:1 ratio for Mg to O, the experiment established a process to determine the empirical formula. The experiment calculated a relatively high percentage error. Errors may have occurred in the process including the use of the inadequate bunson burner and not allow sufficient time to warm the crucible after distilled water was added. However, the process did allow for calculations to be made regarding the empirical formula for magnesium oxide, percentage error, and standard…

    • 408 Words
    • 2 Pages
    Good Essays
  • Better Essays

    Get Charged Up Lab Report

    • 1848 Words
    • 6 Pages

    To accomplish this, three different methods were used. Titration was used to react NaOH with HCl to determine the amount of H+ left over after the reaction is complete. Crystallization was used to determine the amount of MgCl₂ made after the reaction is done. Both of these methods allowed us to calculate the amount of H+ reacting with the amount of Mg. The gas law method and the Ideal Gas Law was also used to determine the mole ratio of magnesium metal to hydrochloric acid by measuring the amount of hydrogen gas based on the pressure and temperature changes during the reaction. With the results from each procedure, graphs were constructed and the most accurate and precise method was discernible.…

    • 1848 Words
    • 6 Pages
    Better Essays
  • Satisfactory Essays

    Ilab Chemistry Lab

    • 451 Words
    • 2 Pages

    The purpose of this lab was to determine the atomic weight of magnesium by measuring the amount of hydrogen gas evolved when hydrochloric acid reacted with magnesium. In order to measure the atomic weight I needed to measure the amount of the hydrogen gas that was evolved in reaction to the acid of the magnesium. The reaction used was: Mg + 2HCl --> H2 + Mg2+ (aq) + 2Cl- (aq). The major findings of this experiment were that there was a chemical reaction between hydrochloric acid and magnesium, and the reaction produced the hydrogen gas. The results also indicated how many moles of hydrogen gas were equal to the amount of moles of magnesium consumed.…

    • 451 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Chem Lab - Hydration

    • 1038 Words
    • 4 Pages

    Using the formulas, [mass of anhydrous compound x (1 mole/ molar mass of anhydrous compound)] and [mass of water x (1 mole/molar mass of hydrate)] we calculated the moles of anhydrous CaSO4 and moles of water eliminated. Using the results from both trials we calculated the average formula.…

    • 1038 Words
    • 4 Pages
    Good Essays
  • Good Essays

    The purpose of the experiment was to find the percent of water in Epsom salts by heating it. To find the percent of water in a hydrate, the hydrate must be heated. The experiment did not only show how dehydration occurs, but this experiment also gives an accurate and definite portrayal of the amount of water that is removed…

    • 604 Words
    • 3 Pages
    Good Essays
  • Better Essays

    Titration Lab Report

    • 1876 Words
    • 8 Pages

    Primarily, hard water consists of magnesium and calcium. Therefore the ratio of magnesium to calcium ions was inferred to be 50/50. The average molar mass of the molar mass of Magnesium (24.305 g/mol) and the molar mass of Calcium (40.078 g/mol) was calculated to be 32.192 g/mol. This calculated average molar mass was used as the molar mass of the metal that was present in the sample. The concentration of metal that was present in the TAP water was solved by the following calculations:…

    • 1876 Words
    • 8 Pages
    Better Essays
  • Powerful Essays

    water provides partial positive and partial negative charges to which other polar molecules can attach. When ionic solid dissolves, anions and cations dissociate.…

    • 2983 Words
    • 13 Pages
    Powerful Essays
  • Good Essays

    The mass percent of water was determined using the mass of water and dividing it by the total mass of the hydrate and then multiplying that answer by 100%. The number of moles of water in a hydrate was determined by taking the mass of the water released and dividing it by the molar mass of water. The number of moles of water and the number of moles of the hydrate was used to calculate the ratio of moles of water to moles of the sample. This ratio was then used to write the new and balanced equation of the dehydration process. The sample was then rehydrated to the original state and the percent of the hydrate recovered was calculated by using the mass of the rehydrated sample by the mass of the original hydrate and then multiplied by 100%.…

    • 823 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    Hydrate Composition

    • 1334 Words
    • 6 Pages

    By calculating the difference in the mass of the hydrate copper (II) sulfate and the anhydride we were able to determine the mass of water in the hydrate. This information was then used to determine the empirical formula of the hydrate, defined as a compound formed by the addition of water to another molecule. In the first trial, the mass of water in the hydrate was determined to be 0.41 g, while in the second trial the mass of water was 0.52 g. Moles of water associated with a single mole of anhydride were then calculated for both trials, giving the values of 4.7 and 4.5 moles of water, respectively. This indicated that the empirical formula of the hydrate might be copper (II) sulfate pentahydrate – CuSO4·5H2O.…

    • 1334 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    Farhampton Inn

    • 498 Words
    • 2 Pages

    one can calculate the mass of the oxygen that reacted with the magnesium. To obtain good results…

    • 498 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Hydrate Lab Conclusion

    • 378 Words
    • 2 Pages

    Conclusion 1: In this first lab we attempted to discover which of the materials given to us were hydrates by heating them and then dissolving them in water. Our results showed that all of our substances were hydrates besides the sucrose, sucrose if the only one which did not both bring condensation when heated and dissolve in water, which agreed with our hypothesis because we also thought that sucrose was going to be the only one that wasn’t a hydrate. The only error that we may have encountered in this lab was that when heating, the flame was not always the same temperature, but I feel as though this did not affect our data much because we didn’t need a set temperature, we were only seeing if the substance brought condensation. We could have improved out data by comparing our data with other groups and talk about our data if we got different answers. Further questions I could ask are, are there some hydrates that release water faster than others?…

    • 378 Words
    • 2 Pages
    Good Essays
  • Powerful Essays

    Hydrated ionic compounds are regular ionic compounds that contain a specific number of water molecules in their respective crystals. Hydrates that spontaneously lose water to the atmosphere are known as efflorescent. Compounds that spontaneously absorb water from the atmosphere are known as hygroscopic. Each ionic hydrate has a fixed water of crystallization, and this varies for…

    • 2397 Words
    • 10 Pages
    Powerful Essays
  • Good Essays

    Chemical compounds that contain discrete water molecules as part of their crystalline structure are called hydrates. Hydrates occur quite commonly among chemical substances, especially among ionic substances. More often than not, such compounds are either prepared in, or are recrystallized from, aqueous solutions. Hydrates exist for ionic compounds most commonly, but hydrates of polar and non polar covalent molecules are also known. In this experiment, you will study some of the properties and characteristics of several ionic hydrates, and then you will determine the percentage by weight of water in an unknown hydrate as well as its mole ratio of water to anhydrous salt.…

    • 1762 Words
    • 8 Pages
    Good Essays
  • Good Essays

    Chemistry IA

    • 399 Words
    • 2 Pages

    Number of moles of H2 is the same and Mg. Therefore, moles of H2 = 0.001028…

    • 399 Words
    • 2 Pages
    Good Essays

Related Topics