percent water in a hydrate lab answer key

The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. the aluminum dish and Epsom salt to Data Table 1. Balance Included are labs on the following. This product contains 13 pages of chemistry multiple choice WITH ANSWERS on calculating the mass percent of an element, calculating the percent composition of a compound, determining a compounds empirical formula from percent data or mass data, determining the molecular formula of a compound and solving for the number of water molecules in a hydrate. Furthermore, in order to determine the exact name of the hydrate, we must find out the ratio between the anhydrate and water that are associated with the hydrate. BOLD and Change the color of your answer to RED so the teacher could easily find them! View Notes - hydrate-lab-answers from CHEM 113 at Brigham Young University. What is a hydrate? Because the number of moles of water was lower than what it could have been originally, the ratio of water to anhydrate was 6:63:1 rather than 7:1. c. Change in the strength of the heat while maintaining the same amount of time to heat. The water is chemically combined with the salt in a definite ratio. Mass of hydrate 4. Since copper (II) sulfate is usually a bright blue due to Cu. (0.3610 g /1.000 g) (100) = 36.10%. If we had either heated the beaker with a strong flame from the beginning or increased the amount of time of heating, the number of moles of water during calculation could have been larger. Second, it will also determine the molar ration of water to inorganic salt in Epsom salt. Keep in mind, that you have to use your own data and no two reports can be exactly the same. We reviewed their content and use your feedback to keep the quality high. water of hydration pre lab answers. Masses are measured beforeheating to determine the mass of theoriginal sample (the hydrate)andafterheating to determine the mass of copper (II) sulfate (CuSO4) anhydrous. Cross), Civilization and its Discontents (Sigmund Freud), Chemistry: The Central Science (Theodore E. Brown; H. Eugene H LeMay; Bruce E. Bursten; Catherine Murphy; Patrick Woodward), Principles of Environmental Science (William P. Cunningham; Mary Ann Cunningham), Campbell Biology (Jane B. Reece; Lisa A. Urry; Michael L. Cain; Steven A. Wasserman; Peter V. Minorsky), Topics for Exam 4 - Summary General Chemistry, Laboratory techniques option one report (1) Nicholas Mc Quagge, and magnesium sulfate, also known as Epsom salt. Show work, include units, and put your answers in the blanks. Students dehydrate copper (II) sulfate pentahydrate, crucible or evaporation dish and use their data to determine the % composition and the number of, molecules per formula unit of copper (II) sulfate. = 0.08158 mol / 0.009273 mol = 8.80 mol H, = 0.08158 mol / 0.009125 mol = 8.94 mol H, = 0.08158 mol / 0.006120 mol = 13.3 mol H, | (actual value - experimental value) / actual value | x 100%, From this lab, we are able to conclude that our prediction was strongly supported in both terms. Elena Lisitsynacontributed to the creation and implementation of this page. Look it up if you have to! Then, they heat the, experimentally. The difference between the hydrate mass and anhydrate mass is the mass of water lost. First, this experiment is focusing on how to determine the water content of a hydrate by heating. Describe the changes you can observe during the heating process. 6. Record the final mass of the anhydrous salt in you lab notebook and do the calculations to show that the molar ratio of water to anhydrous salt really is 5:1. Hydrated and anhydrous are discussed along with percent error. Answer1) A hydrate is a solid ionic compound that contains specific number of water molecules in its crystal structure. Little or no prior knowledge of finding empirical formula necessary. The last idea we learned was how to apply the knowledge of colors of specific ions and solids. By doing this, it figured out that the . In this experiment, you will be heating a hydrate of copper (II) sulfate (CuSO4nH2O) to evaporate the water. Each type of hydrate traps water in its own unique way, but heating a hydrate will release the If not, repeat the heating/cooling/weighing process until two successive weighing have the same mass. First, the assumption that the hydrate is associated with magnesium sulfate due to its white appearance is proven to be correct. 7H 2 O) is a heptahydrate of magnesium sulfate: within one mole of magnesium sulfate heptahydrate are seven moles of water. Such compounds ar, compounds that have a specific amount of wat, writing the formula of a hydrate, a dot connects t, that of water and is viewed as an addition sign i, lose all or part of their water of hydration when e, this dehydration is accompanied by a colour chang, Give Me Liberty! Our unknown hydrate may be a hydrate of copper(II) sulfate, magnesium sulfate, iron(III) chloride, or iron(III) nitrate. The hydrate was heated until all the water evaporated, and the mass of the remining anhydrous, salt was measured. This water can be driven off by heat to form the anhydrous (dehydrated) ionic compound, magnesium sulfate. Minutes, written for Hotplate or Bunsen burner.Students: Observe, leaving compound as steam Heat to constant mass Calculate, the anhydrous compoundLab Contains: Student, , students heat epsom salt to drive off the, the crystal lattice. Once we know how much water is needed for each magnesium sulfate, we can then name the substance in MgSO 4 x H 2 O, where x represents the ratio. A 5.0 g sample of a hydrate of BaC12 was heated, and only 4.3 g of the anhydrous salt remained. Final mass ofAnhydrousCuSO4(without water), Moles of CuSO4in the anhydrous mass (mass / 159.5), Ratio between moles of water /moles of anhydrous copper sulfate, Final mass ofAnhydrousMgSO4(without water), Moles of MgSO4in the anhydrous mass (mass / 120), Ratio between moles of water /moles of anhydrous Magnesium sulfate, THIS DATA TABLE IS NOT FOR 2020-2021 STUDENTS, Data Table Lab #1 with triple beam balance, Mass after heating (First time) beaker + glass rod + CuSO45H2O, Mass after heating (Second time) beaker + glass rod + CuSO45H2O, (Mass of beaker + glass rod + CuSO45H2O Mass after heating (Second time), Data Table Lab #2 with triple beam balance, Mass after heating (First time) beaker + glass rod + mGSO4, Mass after heating (Second time) beaker + glass rod + mGSO4, Final mass ofAnhydrous MgSO4(without water-Lowest number you got), Moles of MgSO4in the anhydrous mass (mass / 159.5), (Mass of beaker + glass rod + MgSO45H2O Mass after heating (Second time), I am text block. nhi chung general chemistry chem 1411, hcc 11 november, 2017 post lab formula of hydrate and percentage of water of hydration introduction the purpose of this From the calculation, you can clearly see that the units of g/mol in the numerator and denominator cancel out. Click edit button to change this text. based on the chemical formula. Measure out 2 to 3 g of the magnesium sulfate in the crucible. Why do hydrates form? You will watch the video (link provided) and obtain the data from the video. You have just come across an article on the topic water of hydration pre lab answers. Use the information to answer the questions. ring stand Thus, the ratio between water and magnesium sulfate will be close to being 7:1. 1) The process you will execute in this lab is similar to _____, which a separation process that exploits differences in _____ between . Calculate the Average % of Water in the Hydrate Samples. xH2O). when we heat blue CuSO5HO, what happens? Use the glass end to stir the compound. Calculate the percent water in the hydrate sample, using Equation 2, percent water, % = (mass of water lost, g/mass of hydrate heated, g) (100%), determine the mass of a hydrated salt sample and the mass of the residue after heating the sample; from these masses you will calculate the mass of water lost during heating and the percent water in the hydrate, crucible and cover, crucible tongs, Bunsen burner, ring stand and support ring, pipe-stem triangle, ceramic-centered wire gauze, microspatula, balance, preparing and weighing crucible; heating and weighing unknown hydrate. The, requires bunsen burners, rings, ring stands, crucibles, crucible tongs, and balances. An additional challenge is that both the hydrate and anhydrous salt are white.Finally, unless you frequently stir the crystals they will combine and harden, possibly trapping water inside To prevent stir continuously. , we can exclude that option from our prediction. remove the burner in case of excess spattering. 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 ratios between molecules are in integers, but as this is an experiment, it will be more likely to acquire the ratio in decimal points. While these do not have teacher directions, most labs are fairly self-explanatory and have materials lists provided. In this lab, we learned how to apply stoichiometry in a new way to determine a formula of a hydrate. Magnesium sulfate, the only left option, is white in appearance which makes it a possible identification for our hydrate. By taking mass measurements before, during, and after, students can then calculate the, .It is presented to students as an "unknown", and based on their calculations they determine which, . Thus, the ratio between water and magnesium sulfate will be close to being 7:1. Use the dropper to add a very little water to the anhydrous copper (II) sulfate. The mass of water evaporated is obtained by subtracting the mass of the anhydrous solid from the mass of the original hydrate (\ref{3}): \[m_{\ce{H2O}} = m_{\text{Hydrate}} - m_{\text{Anhydrous Solid}} \label{3}\]. Add between 0.3 and 0.8 g of Epsom salt to the metal dish, then add the combined weight of. Calculate mass of hydrate heated 2. GCC CHM 090 GCC, 2006 1 of 2 Names: _____ Lab Exercise: Percent Water in a Hydrate Introduction: A hydrate is a crystalline solid that traps water as part of its crystal structure. The exact definition of a hydrate - any substance that contains some amount of water molecules in its structures - was illustrated in a precise way in this experiment. White monohydrate form is available at 110C, while the anhydrous form can be isolated near 250C. iron ring how long should you heat the crucible at an angle? 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 salt is magnesium sulfate MgSO4and, the same as Copper sulfate, it exists as a hydrate, but in this case we will find the amount of water surrounding the compound. crucible & cover I ; O j CJ OJ QJ U56OJ QJ \] 56CJ OJ QJ \] j CJ OJ QJ CJ H*OJ QJ CJ H*OJ QJ 5>*CJ OJ QJ \5CJ OJ QJ \ CJ OJ QJ 6CJ OJ QJ ]: m n * M N Z } ~ ( dh &. TPT empowers educators to teach at their best. Place the crucible in the clay triangle. percent water in a hydrate lab answers. Calculate mass of water in hydrate sample. What percentage of water is found in CuSOp5H20? Accessibility StatementFor more information contact us atinfo@libretexts.org. The ratios of other three substances were incongruous to each other. Want to include, experiment that correlates with Stoichiometry? The moles of water and inorganic salt in Epson salt were separately calculated and. Calculate mass of water in hydrate sample. If clumps are formed, just continue stirring and heating until you see. 9H2O), 1.48g CuSO4x 1 mol CuSO4/ 159.61g mol-1CuSO4 = 0.009273 mol CuSO4, 1.47g H2O x 1 mol H2O / 18.02g mol-1H2O = 0.08158 mol H2O, number of moles H2O / number of moles CuSO4, = 0.08158 mol / 0.009273 mol = 8.80 mol H2O / 1 mol CuSO4 (3 significant figures), 1.48g MgSO4x 1 mol MgSO4/ 120.36g mol-1MgSO4= 0.01230 mol MgSO4, number of moles H2O / number of moles MgSO4, = 0.08158 mol / 0.01230 mol = 6.63 mol H2O / 1 mol MgSO4, 1.48g FeCl3x 1 mol FeCl3/ 162.20g mol-1FeCl3= 0.009125 mol FeCl3, number of moles H2O / number of moles FeCl3, = 0.08158 mol / 0.009125 mol = 8.94 mol H2O / 1 mol FeCl3, 1.48g Fe(NO3)3 x 1 mol Fe(NO3)3/ 241.86g mol-1Fe(NO3)3= 0.006120 mol Fe(NO3)3, number of moles H2O / number of moles Fe(NO3)3, = 0.08158 mol / 0.006120 mol = 13.3 mol H2O / 1 mol Fe(NO3)3. The water in a hydrate is bound loosely, and so is relatively easily removed by heating. how should crucible FIRST be arranged on ring? I give you teacher set up instructions, has an introduction to help students understand why they are doing the, from copper (II) sulfate pentahydrate by heating and determine the empirical formula. Its experimental ratio was 6.63 to 1 and its expected ratio was 7:1. Use the balance to weigh the metal dish with the number 1 label and record the weight in Data, 3. So the correct chemical formula is S r c l 2.2 waters for the next 1 37.2% water or 100 g of the compound gives us 32.7 g water Which will convert to moles water by dividing by its smaller mass, the remaining percentage is 62.8. 1.) KEY. Why Do Organism Look Like the Way They Do. Then allow it to cool and weigh it. Hydrates are ionic compounds (salts) that have a definite amount of water (water of hydration) as part of their structure. To calculate the percent composition, we took the mass of each part of the substance and divided it by the total mass. What experimental evidence would you have to indicate you inadvertently, Determine the mass percent of each element present in. The hydrate was heated until all the water evaporated, and the mass of the remining anhydrous salt was measured. Identity of the Hydrate:MgSO47H2O Magnesium heptahydrate, % Error = | (actual value - experimental value) / actual value | x 100%, = | (6.63 - 7.00) / (6.63) | x 100% = 5.58% Error. 5 min; position burner so inner cone of flame directly contacts lower edge of crucible bottom; heat until crucible bottom turns slightly red; heat 10 min, allow crucible to cool for ____ on the ____; then, 5-10 min; triangle; place on wire gauze to finish cooling, AP Chemistry Lab Quiz 1: % Water in a Hydrate, CHEM Lab: Determining the Percent Water in an, LAB 4 ISOLATING THE COMPONENTS OF A THREE- CO, Percent Composition and Molecular Formula Ass. Heat. Determine the percent water of hydration in a hydrate sample. So we have 62.8 g of nickel to nitrate. Nearly half of the mass of the hydrate is composed of water molecules within the . By knowing that ions such as Cu, have their designated colors, we were able to eliminate three options for the anhydrate, FeCl. Be sure your beaker and glass rod does not have any crack, and that that they are clean and dry. 5 waters of hydration. Then the larger number of moles of water divided by the smaller number of moles of anhydrate could have produced a higher ratio that is closer to 7:1 than what we got. Become Premium to read the whole document. Divide the mass of the water lost by the mass of hydrate and multiply by 100. how are the waters of hydration included in the chemical formula? Iron (III) sulfate has a purple tint to it, and has a crystalline structure. View WS More Hydrate Lab Practice Answer Key.pdf from CHEM 151 at Leeward Community College. Sometimes the water is liberated in stages, with one or more lower hydrates being observed during the heating process. Your Lab Reports are individual assignments, but you're welcome to communicate with your group and discuss the results. Calculate the mass of water lost from . We believe our hydrate was magnesium sulfate, because the unknown hydrate was more closely related in physical appearance to that of magnesium sulfate, compared to the the three other options. The hydrate contains water as a. Integral part of the crystalline structure. Purpose: Determine the percent of water present in a hydrated copper (II) sulfate (CuSO 4 n H 2 O) and Epson Salts. The change, mass observed allows them to calculate the amount of, COMPOSITION EMPIRICAL FORMULA Multiple Choice Grade 11 Chemistry (13 PG), This product contains 13 pages of chemistry multiple choice WITH ANSWERS on calculating the mass, data or mass data, determining the molecular formula of, 12 font, times new roman, without text boxes and condensed into the least amount of space possible. Ans: 47.24 %. Without water. 7H 2 O) is a heptahydrate of magnesium sulfate: within one mole of magnesium sulfate heptahydrate are seven moles of water. Record any qualitative observations (i. spattering, spilling, smoke). Answer: _____ b) Calculate the number of moles of water in the hydrate sample that were driven off by heating? Lab 09 - Percent of Water in a Hydrate Pre-Lab Questions Date: Name: - Section: Instructor: - Read the following laboratory experiment and answer the questions below. Mass of water. Once the numbers of moles of two substances are known, the ratio can be computed by dividing them. Hydrate Math The percent of water in a hydrate can be determined in a manner similar to determining the percent composition of a compound. Mass of dish + anhydrous salt (after heating) 5. This water can be driven off by heat to form the anhydrous (dehydrated) ionic compound, magnesium sulfate. This means we can exclude these three options from our prediction. Hydrates are ionic compounds that contain water molecules as part of their crystal structure. ("n" in SrCl2nH2O) Section 1: Purpose and Summary . These mu, compound. represents the ratio. The error being only 5.58%, the overall ratio of water to magnesium sulfate was somewhat accurate. 1. From the masses of the water and anhydrous solid and the molar mass of the anhydrous solid, the number of moles of water and moles of the anhydrous solid are calculated as shown below (\ref{4}, \ref{5}): \[n_{\ce{H2O}} = \frac{m_{\ce{H2O}}}{MM_{\ce{H2O}}} \label{4}\], \[n_{\text{Anhydrous Solid}} = \frac{m_{\text{Anhydrous Solid}}}{MM_{\text{Anhydrous Solid}}} \label{5}\]. Answer the questions below. A student performed the experiment correctly and the initial massing correctly, but forgot to mass the crucible cover after heating. 2.) 7H2O) is a heptahydrate of magnesium sulfate:within one mole of magnesium sulfate heptahydrate are seven moles of water. The theoretical (actual) percent hydration (percent water) can be calculated from the formula of the hydrate . mass lost after first heating 4.8702g - 3.0662g = 1.8040g. the ratio was determined by dividing the moles of water by the moles of inorganic salt. How many moles of water did you have in your original sample? This is a Premium document. This phenomenon could have deviated the ratio by causing a loss in the amount of water and anhydrate. To make sure that, each element has the equal number of atoms on both sides of the equation, coefficients were. To calculate the molar mass, we added up each element's atomic mass for each part of the substance. Experts are tested by Chegg as specialists in their subject area. Stop heating when the salt has lost all traces of blue color. . According to a smaller ratio compared to the expected ratio, more water was probably lost during this occurrence, which lowered the number of water moles. This hydrate was previously mentioned in class to be magnesium sulfate heptahydrate. Lab: Determining the Composition of a HydrateFor students in Grades 8-12.INTRODUCTION:Hydrates are ionic compounds that have a number of water molecules attached as part of their structure. T T , t _' l K K K K K 2 2 2 &. How can original hydrates be regenerated? water lost by the hydrate. The procedure is clearly defined so that there is no question about the proper way to safely perform the. magnesium sulfate hydrate lab answers. : an American History, 3.4.1.7 Lab - Research a Hardware Upgrade, BUS 225 Module One Assignment: Critical Thinking Kimberly-Clark Decision, The Deep Dive Answers - jdjbcBS JSb vjbszbv, Lessons from Antiquity Activities US Government, CWV-101 T3 Consequences of the Fall Contemporary Response Worksheet 100%, Piling Larang Akademik 12 Q1 Mod4 Pagsulat Ng Memorandum Adyenda at Katitikan ng Pulong ver3, Leadership class , week 3 executive summary, I am doing my essay on the Ted Talk titaled How One Photo Captured a Humanitie Crisis https, School-Plan - School Plan of San Juan Integrated School, SEC-502-RS-Dispositions Self-Assessment Survey T3 (1), Techniques DE Separation ET Analyse EN Biochimi 1. a) If the sample was heated to constant weight after reheating, what is the minimum mass that the sample can have after the second weighing? However, as we dehydrated the hydrate and discovered that a hydrate is made of some anhydrate and water with a certain ratio, we soon realized what a hydrate actually was. First, it is so easy to set upnot much prep at all.

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