Chem181_Lab3_Microchem_precip_lab_solubility_table

Complete Table 6 using the written data and given information in Table 2 Part 1: Effect of Concentration The first part of the experiment is carried out at constant (room) temperature. Trial 1 is your baseline measurement. In Trials 2 and 3 you will change the concentration of Solution #1 or Solution #3, respectively. Table 2. Effect of reactant concentration on reaction rate Soln #2 0.0025 M Soln #1 0.10 M KI 20.0 mL Na₂S₂O3 10.0 mL 10.0 mL 10.0 mL 20.0 mL 10.0 mL Trial 1 2 3 1 Time (s) Trial (n) [1] 2 Table 6: Ion Concentrations in Reaction Mixture 3 Temp. (°C) I min 17 21°C 2 min 27 21°C 3 min 13 21°C C 0.040 mol/L [S₂O3²] [S₂08²] Water 0.0 mL 10.0 mL 10.0 mL Starch [ [ 3 drops 3 drops 3 drops Soln # 3 0.10 M (NH4)2S2O8 20.0 mL 20.0 mL 10.0 mL Total Vol. % Change in lon Concentration Relative to Trial 1 ] decreased by ] decreased by 50.0 mL 50.0 mL 50.0 mL % %

Mg + 2HCl → MgCl2 + H2 This experiment was performed two times. All values are valid to one decimal place. If the decimal place is not shown, add a ".0" Experiment Mass of Mg (mg) Starting Temperature (°C) Final Temperature (°C) 1 2 19.6 20.7 19.5 20.7 33 33.5 The previous page contained data from two experimental runs for the reaction between magnesium and hydrochloric acid. Mg+ 2HC! MgCl2 + H2 First, how many moles (n) of Mg reacted with the HCI? Use the average value of the two masses from your provided data set. Answer: 0.001658 I Mg + 2HCI MgCl2 + H2 Next, what is the amount of heat absorbed by the water (qsurr) in the experiment? Use the average AT from your data to calculate a single value for q. Report your answer in J. Remember to consult the lab manual and/or the video for any values you might need. Answer: Mg + 2HC! MgCl2 + H2 Finally, calculate A,H for this reaction and report your answer in kJ/mol. Answer:

phs.blackboard.com/webapps/assessment/take/take.jsp?course_assessment_id%3D 36688_1&course_id%3D_31958 1&content_id%3_1130567_1&- 8r 10 13 140 15 16 20 11 12 17 18 19 20 A Moving to another question will save this response. Quèstion 6 Select the statement that is not supported by the following equation: q=0=(mwater)(Cwater)(ATwater)+ (mmetal)(Cmetal)( ATmetal) The total change in heat is the sum of the changes in heat of water and a metal. Energy is conserved. Energy is transferred between water and a metal. Energy is lost during a calorimetry experiment. A Moving to another question will save this response. hp & %23 9. 6. 00 进3

Complete the table and write the chemical reactions

Convert each "b" value from the three Graphs ln(Conc) to the Initial Concentration. Graph Two:  y= -0.0048x -11.125 Graph Four: y= 161824x - 13.326  Graph Five: y= -0.0189x -10.903  **Note these are the y= mx-b equation from the linear graph,  In(concentration) vs time. I don't know how to convert natural log value such as -11.125 to the initial concentration.

Find the Final volume of buret (mL) and the Concentration of NaOH (M )

If this item does not open automatically you can open Data Sheet here = 106106334 Part I. Reaction of Fe³+ and SCN™ Test tube A B C 5 Adding NH3 (aq) 1/1 Action performed Experiment 15 Chemical Equilibrium and Le Châtelier's Principle Adding Fe(NO3)3 (aq) Adding NaSCN (aq) Adding NaNO3(aq) Part II. Reaction of Cu²+ and aqueous NH3 Action performed Mixing CuSO4 and NH3 (aq). Oll y 31 88% + Data Sheet Observations Observations. DELL العال[ O : * 8 CH127 Introductory General Chemistry Laboratory Conclusion Conclusion O Dec 18 8:09 2 3 Р

Need help filling this out. It is the Data Sheet for Ch. 2 Qualitative Analysis. Very much appreciated!

What is calibration and why is it essential in relation to food analysis? Provide examples.

||| O CHEMICAL REACTIONS Balancing chemical equations with interfering coefficients Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients. CH,CH, (g) + O,(g) → CO,(g) + H,O(g) X Ś

Ca2+ in a drinking water sample was analyzed by the following reactions below: Ca2+(aq) + C2O42-(aq) → CaC2O4 (s) → CaO(s) + CO(g)+ CO2(g) First an excess of C2O42- was added to 0.10 L of the Ca2+ water sample. Then CaC2O4 was precipitated, which was demcomposed into CaO with filtering and some heat. The CaO was measured to be 5.61 mg. What is the concentration of Ca2+ in the original water sample? The MW of CaO is 56.1 g/mol.      0.0100M     0.0010 M     1.00 M     0.100 M   The partition coefficient (K) of methylamine (CH3NH2) is 4.50, preferring the organic layer over the aqueous layer in this extraction. The Ka of methylammonium (CH3NH3+) is 2.00 x 10-11. If 10 mL aqueous methylamine solution at pH 11.0 is extracted with 20.0 mL organic solvent, what is the fraction of solute remaining in the water (q)?   HINT: methylamine is a weak base.     14.3%     10.0%     18.2%     81.8%

Part IV Cabbage Juice Indicator Chop cabbage into small pieces until you have about 2 cups of chopped cabbage. Boil for at least ten minutes to allow time for the color to leach out of the cabbage. Allow it to cool for 15 min • Filter out the plant material to obtain a red-purple-bluish colored liquid. 1. Add 1-2 drops of cabbage juice into a small bowl 2. Add 3-5 drops of vinegar into the bowl with the cabbage juice 3. Observe Is this a chemical change or physical change? Explain? Store the excess cabbage juice in your refrigerator, you will need them for future experiments.

For the reaction 2N2O5(g) ® 4NO2(g) + O2(g), the following data were collected.   t (minutes) [N2O5] (mol/L)   0 1.24 x 10–2   10 0.92 x 10–2   20 0.68 x10–2   30 0.50 x 10–2   40 0.37 x 10–2   50 0.28 ´ 10–2   70 0.15 ´ 10–2         The initial rate of production of NO2 for this reaction is approximately:   A) 6.4 x10–4 mol/L • min   B) 3.2 x10–4 mol/L • min   C) 1.24 x 10–2 mol/L • min   D) 1.6 x 10–4 mol/L • min   E) none of these

In a Gravimetric Analysis of Chloride experiment, why is it necessary that the samples are left in a dark drawer (cabinet) for a week before the precipitate is collected?

Failm HCO, (aq) + H₂SO4 (aq) →? Express your answer as a chemical equation. Identify all of the phases in your answer. ΑΣΦ ← A chemical reaction does not occur for this question. Submit Request Answer Part B ? CO2 (aq) + HNO3(aq) →? Express your answer as a chemical equation. Identify all of the phases in your answer. ΑΣΦ Submit Request Answer ? A chemical reaction does not occur for this question.

What should I put in the box

Remaining Time! 02:29:4. Consider the balanced chemical equations shown below. When a 6.00 g sample of a mixture of iron (Fe) and aluminum (Al) is treated with excess HCl(aq), 0.177 moles of H2 are obtained. What is the mass percentage of Fe in the original mixture? Choose the closest answer. Fe(s) + 2 HCI(aq) FeCl2(aq) - + H2(g) 2 Al(s) +6 HC((aq) 2 AICI3(aq) + 3 H2(g) 96 % 69 % 47 % 33 % 17 % Rack Question Menu - O O

30jud to 28AM basu mw 5. Sodium carbonate is a reagent that may be used to standardize acids in the same way that you have used KHP in this experiment. In such a standardization it was found that a 0.498-g sample of sodium carbon- ate required 23.5 mL of a sulfuric acid solution to reach the end point for the reaction.

What would the balance reaction be for both of them?

21. What materials contain a precisely known concentration of a substance typically used in quantitative analysis?   A. ACS grade MaterialsB. Chemical Standard MaterialsC. IUPAC Standard MaterialsD. PIPAC Standard Materials

1. A student performed this experiment and obtained the following concentration values: 0.02813 M, 0.02802, and 0.02788 M a. what is the mean concentration? b. what is the standard deviation of these results? 3. how would the following errors affect the concentration of Cl- obtained in question 2b? give your reasoning in each case. a. the student read the molarity of AgNo3 as 0.02104M instead of 0.02014M b. the student was past the endpoint of titration when he took the final buret reading.