Preparation of a Coordination Compound. Step 1 Copy the balanced equation for the preparation of FeC 2 O 4.. 3H2 O from FeC 2 O 4. Mass of watch glass

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1 Student Name Lab Partner Demonstrator Lab Section DATA SHEET Marking scheme Prelab exercise Lab performance Sig figs, units Calculations Crystals Preparation of a Coordination Compound Step 1 Copy the balanced equation for the preparation of FeC 2 O 4. 2H2 O. Mass taken of FeSO 4 (NH 4 ) 2 SO 4. 6H2 O or mol Mass of H 2 C 2 O 4. 2H2 O or mol Limiting reagent is Theoretical yield of FeC 2 O 4. 2H2 O mol Step 2 Copy the balanced equation for the preparation of K 3 Fe(C 2 O 4 ) 3. 3H2 O from FeC 2 O 4. 2H2 O. Theoretical yield of K 3 Fe(C 2 O 4 ) 3. 3H2 O (based on FeC 2 O 4. 2H2 O as limiting reagent) mol and in grams g Mass of watch glass and K 3 Fe(C 2 O 4 ). 3 3H2 O Mass of watch glass Yield of K 3 Fe(C 2 O 4 ). 3 3H2 O Percent Yield of K 3 Fe(C 2 O 4 ). 3 3H2 O Description of product crystals, i.e. size, colour, shape, etc. :

2 WORK SHEET Keep extra digits in all calculations when possible. Keep track of the extra digits by underlining or bracketing them. Do not show calculations to find molar mass. Step 1 Calculate moles of FeSO 4 (NH 4 ) 2 SO 4. 6H2 O Calculate moles of H 2 C 2 O 4. 2H2 O Limiting reagent - explain or show mathematically why you choose this to be the LR (Do not just give the definition of a LR) Step 2 Calculate the theoretical yield, in grams, of K 3 Fe(C 2 O 4 ) 3. 3H2 O Calculate the percent yield of K 3 Fe(C 2 O 4 ) 3. 3H2 O

3 Prelab Exercise Name This exercise reviews the calculations associated with this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. (Do not show calculations to find molar masses.) a. If you weighed out the following quantities of each reagent, which would be the limiting reagent in Step 1, the synthesis of FeC 2 O. 4 2H2 O? Show and explain your work. Ferrous ammonium sulphate hydrate 2.45 g Oxalic acid hydrate 1.35 g b. Using your data from question a, calculate the theoretical yield in grams of the potassium trioxalatoferrate (III) trihydrate complex.

4 Student Name Demonstrator Lab Section DATA SHEET Marking scheme Prelab exercise Lab performance Sig figs, units Calculations NaOH and Unkn Acid-Base Titration, a Quantitative Analysis Part 1 Standardization of NaOH solution Mass of boat and sample Mass of boat after transfer Mass of sample transferred Final burette reading Initial burette reading Volume of NaOH Calculated molarity of NaOH Lab. average molarity of NaOH (from your demonstrator) % deviation of your value from lab. average Part 2 Molar Mass of an Acid Unknown # i a = Mass of boat and sample Mass of boat after transfer Mass of sample transferred Final burette reading Initial burette reading Volume of NaOH Calculated molar mass Average values for the molar mass of the acid - the averages below will be the same number but may have different SF Average molar mass of the acid ( SF method) Average molar mass of the acid ssd (ssd method)

5 WORK SHEET Use extra digits in all calculations when possible. Part 1 Molarity of the NaOH Calculate the molarity of NaOH solution equation (3) Calculate the % deviation of your [NaOH] from the class average value Part 2 Molar Mass of Unknown Acid - show calculation for one run only Calculate the molar mass of the acid unknown - use the class average value for the [NaOH] equation (3)

6 Average Molar Mass Of the Unknown Acid - Read the instructions carefully. List all four values from lowest to highest. You may use all four values to calculate the average, or you may use the three closest values. Calculate the range of the three lowest and the range of the three highest. If the ranges are significantly different then use the three with the smallest range, otherwise use all four. Show the range calculations and clearly indicate whether you will be using three or four values to calculate the average and ssd. Use your calculator to find the average value ( x! ) and sx value (the ssd). The ssd will always have the same units as the average value. You will record the average value twice on the data sheet. Once using the correct SF according to the SF method and once using the ssd to determine the number of SF. x! value sx value ( the ssd )

7 Prelab Exercise Name This exercise reviews the calculations associated with this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. a. A sample weighing g of the primary standard potassium hydrogen phthalate requires ml of NaOH solution for neutralization. Calculate the molarity of the NaOH solution. b. An organic acid has 2 ionizable hydrogen atoms in the molecule g of acid is dissolved in water and titrated with the standardized NaOH solution, question a. The final equivalence point is reached after ml of the base solution have been added. Calculate the molar mass of the acid.

8 Student Name Lab Partner Demonstrator Lab Section DATA SHEET Molar Volume of Nitrogen Gas Marking scheme Prelab exercise Lab performance Sig figs, units Calculations Molar V, Unkn Part 1 Determination of Molar Volume of N 2 (g) Mass of vial and NaNO 2 Mass of vial Mass of NaNO 2 Moles of NaNO 2 Moles of N 2 gas Temperature of N 2 gas C Temperature of N 2 gas K Temperature of water C Volume of N 2 gas Atmospheric pressure Pressure due to H 2 O vapour Pressure of N 2 (g) alone Volume of N 2 (g) corrected to reference conditions Molar volume of N 2 (g) L mol!1 Molar volume of an ideal gas at 25 C, 100 kpa L mol!1 % deviation of my measured molar volume from the ideal

9 DATA SHEET Molar Volume of Nitrogen Gas Part 2 Determination of mass percent of NaNO 2 in Unknown # Mass of vial and Unknown Mass of vial Mass of Unknown Temperature of N 2 gas C Temperature of N 2 gas K Temperature of water C Volume of N 2 gas Atmospheric pressure Pressure due to H 2 O vapour Pressure of N 2 (g) alone Volume of N 2 (g) corrected to 25 C and 100 kpa Your Molar Volume of N 2 from Part 1 Moles of N 2 produced Moles of NaNO 2 in sample Mass of NaNO 2 in sample % by mass of NaNO 2 Average Values for the mass percent of NaNO 2, the two averages below will be the same number but may have different SF Average % by mass of NaNO 2 (SF method) Average % by mass of NaNO 2 ssd Additional Calculation - see work sheet Average % by mass of NaNO 2 (SF method)

10 WORK SHEET Part 1 Determination of Molar Volume of N 2 (g) Calculate moles of NaNO 2 reacted Calculate pressure of N 2 (g) alone, equation (5) Calculate volume of N 2 (g) corrected to reference conditions, K and 100 kpa, equation (3) Calculate molar volume of N 2 (g), equation (4) Calculate the % deviation of your experimental molar volume from that of an ideal gas, L mol!1 Part 2 Determination of NaNO 2 content, show calculations for one run only Calculate pressure of N 2 (g) alone

11 Calculate volume of N 2 (g) corrected to reference conditions Calculate moles of N 2 produced Calculate mass of NaNO 2 reacted Calculate % by mass of NaNO 2 in the sample Average value Write both your % by mass values below and then use your calculator to find the average value ( x! ) and sx value ( the ssd ) for the % by mass of NaNO 2. x! value sx value ( the ssd ) You will record the average value twice on the data sheet. Once using the correct SF according to the SF method and once using the ssd to determine the number of SF. Additional Calculation The results for Part 2 could be recalculated using the actual molar volume of N 2 (g), L mol -1, instead of your molar volume. An easier way to get the same average value is to use the formula given below and your average mass % of NaNO 2. Use the value with the SF according to the SF method. Average Mass % of NaNO 2 x Molar Volume (yours) Molar Volume (given)

12 Prelab Exercise Name This exercise reviews the important calculations associated with this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. a. When g of NaNO 2 is allowed to react with an excess of sulfamic acid solution, the volume of N 2 (g) produced is measured by displacement of 163 ml of water. After the reaction is completed, the temperature of water is 26.0 C and that of gas is 24.0 C. The atmospheric pressure is kpa. Use equations (3, 4 and 5) to calculate the molar volume of N 2 (g) at 25 C and 100 kpa. You may not use PV = nrt. b. When g of a sample containing NaNO 2 and some inert material is allowed to react with an excess of sulfamic acid solution, 128 ml of dry N 2 (g) at 25 C and 100 kpa are obtained. Calculate the percentage by mass of NaNO 2 in the sample with the aid of the molar volume of N 2 (g) at 25 C and 100 kpa from question a.

13 Student Name Lab Partner Demonstrator Lab Section DATA SHEET Prelab exercise Lab performance Sig figs, units Calculations Graph pk a, stock conc. Spectrophotometric Determination of the pk a of an Indicator tube HIn acetic acid acetate ph absorbance colour # ml ml ml ml HCl ml NaOH The ph entries above are calculated in the pre-lab exercise. Model of Spectronic 20 used, analog or digital Indicator concentration, sample tube Indicator concentration, stock solution Calculated absorbance A K for [HIn] = [In2] pk a of bromocresol green K a of bromocresol green

14 WORK SHEET Use the absorption constant,,, for the In2 ion and path length R, given in the strategy and procedure, to calculate the indicator concentration in the sample tube equation (3) Calculate the indicator concentration in the stock solution - before dilution Calculate the absorbance A K, for [HIn] = [In2] equation (4) Find the pk a of bromocresol green indicator from your graph, read to 2 decimal places, label A K and pk a on the graph. pk a = K a =

15 Prelab Exercise Name This exercise consists of important calculations required for this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. You will need these data for your graph! a. Calculate the ph of ml of M HCl after adding ml of indicator solution. Round the ph to three significant figures. Calculate the ph of ml of M NaOH after adding ml of indicator solution. Round the ph to three significant figures. b. Calculate the ph of the nine buffer solutions made by mixing 1.10 M acetic acid and M sodium acetate solutions according to the following proportions. The pk a for acetic acid, CH 3 COOH, is See Introduction for information on SF and log functions. ml 1.10M HAc ml 0.900M Ac ph ( 3 SF ) Show a detailed calculation for one mixture only. The pk a for acetic acid is

16 Student Name Lab Partner Demonstrator Lab Section Marking scheme Prelab exercise Lab performance Sig figs, units Calculations Graphs Unknown DATA SHEET Thermochemistry Part 1 Determination of the Heat Capacity of the Calorimeter Mass of calorimeter dry Mass of calorimeter plus cold water Temperature of cold water + calorimeter Temperature of hot water Final mass of calorimeter plus water Mass of cold water Mass of hot water Extrapolated temperature, T o )T for hot water, T o! T hot K )T for cold water and calorimeter, T o! T cold K Heat capacity of calorimeter, C cal The temperature chart and all grey areas must be filled in and checked by the TA before you leave the lab.

17 DATA SHEET DATA FOR COOLING CURVES (Use ink) TIME min Part 1 Temp C Part 2 Temp C Part 3 Temp C extra Temp C extra Temp C REMEMBER! WEIGH THE CALORIMETER AND SOLUTION AT THE END OF EVERY RUN.

18 DATA SHEET Part 2 The Heat of Neutralization of a Strong Base With a Strong Acid Molarity of standard HCl Final burette reading Initial burette reading Volume of standard HCl used Mass of calorimeter plus final solution Mass of dry calorimeter Mass of final solution Initial temperature of HCl Initial temperature of NaOH Avg temperature of HCl and NaOH, T average Extrapolated temperature, T o )T, T o T average K Specific heat of NaCl solution, c s Heat absorbed by calorimeter + solution Heat of reaction Moles of H + reacted )H neut Average value of )H neut

19 DATA SHEET Part 3 Determination of the Concentration of Strong Acid Solution # Final burette reading Initial burette reading Volume of unknown HCl used Mass of calorimeter plus final solution Mass of dry calorimeter Mass of final solution Initial temperature of HCl solution Initial temperature of NaOH solution Avg temperature of HCl and NaOH, T average Extrapolated temperature, T o )T, T o T average K Specific heat of NaCl solution, c s Heat absorbed by calorimeter and solution Heat of reaction Average Heat of neutralization ( from Part 2 ) Moles of HCl used Molarity of Unknown HCl solution Avg Molarity of Unknown HCl solution ( SF method ) Avg Molarity of Unknown HCl solution ssd (ssd method) Additional Calculation Avg Molarity of Unknown HCl solution ( SF method )

20 WORK SHEET Part 1 The Heat Capacity of the Calorimeter Calculate the heat capacity of calorimeter equation (4) If your value of C cal is negative, check for mathematical errors first, then use C cal = 0 J K2 1 in all subsequent calculations. Part 2 The Heat of Neutralization of a Strong Acid With a Strong Base show calculations for one run only Calculate heat absorbed by calorimeter + solution, q abs = [ C cal ( T o T avg ) + m s c s ( T o T avg ) ] = [ C cal + m s c s ] ( T o T avg ) equation (5) Heat of reaction = q rxn = equation (6) Calculate moles of H + reacted - the limiting reagent Calculate )H neut Write both your values and then calculate the average value of )H neut, x! value

21 Part 3 Determination of the Concentration of Strong Acid Solution show calculations for one run only Calculate heat absorbed by calorimeter + solution, q abs = [ C cal ( T o T avg ) + m s c s ( T o T avg ) ] = [ C cal + m s c s ] ( T o T avg ) equation (5) Heat of reaction = q rxn = equation (6) Calculate moles of H + reacted Calculate molarity of unknown HCl solution Write both your values here and then calculate average molarity and ssd x! value sx value ( the ssd ) Additional Calculation The actual value of the )H neut is kj mol!1. Calculate the molarity of your unknown HCl using this value as follows. Show this calculation. Your average molarity x )H neut (yours) )H neut (given)

22 Prelab Exercise Name This exercise reviews the important calculations associated with this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. a. When ml of 2.92 M HCl are added to 15 ml of 3.07 M NaOH, a measurement shows that 2.35 kj of heat are released. Calculate the heat of neutralization in kj mol2 1. b. Similarly, when ml of HCl of unknown concentration (but less than that of the base) are reacted with 15 ml of 3.07 M NaOH, 2.08 kj of heat are released. From these experimental data, calculate the molarity of the HCl solution.

23 Student Name Lab Partner Demonstrator Lab Section Marking scheme Prelab exercise Lab performance Sig figs, units Calculations DATA SHEET Redox Titration, a Quantitative Analysis Part 1 Standardization of the KMnO 4 Solution Preparation of Na 2 C 2 O 4 solution Mass of weighing funnel & Na 2 C 2 O 4 Mass of clean, dry weighing funnel Mass of Na 2 C 2 O 4 in ml solution Molarity of Na 2 C 2 O 4 solution mol L2 1 Titration Results run # Final burette reading Initial burette reading Volume of KMnO 4 solution Average volume of KMnO 4 used Average molarity of KMnO 4 Class average molarity of KMnO 4 % deviation of my value from the class average value

24 DATA SHEET Redox Titration, a Quantitative Analysis Part 2 Determination of Fe 2+ Content in an Iron Supplement Pill # Pill #1 Pill #2 Pill #3 Mass of powdered pill & boat Mass of empty boat Mass of pill Average molarity of KMnO 4 (your own, Part 1) Final burette reading Initial burette reading Volume of KMnO 4 solution Moles of KMnO 4 Moles of Fe 2+ Fe 2+ content in pill, mg Moles of FeSO. 4 7H2 O Mass of FeSO. 4 7H2 O Mass % of FeSO 4. 7H2 O Average Mass % of FeSO 4. 7H2 O in pill (SF method) Average Mass % of FeSO 4. 7H2 O in pill ssd Additional calculation Average Mass % of FeSO 4. 7H2 O in pill (SF method)

25 WORK SHEET Part 1 Standardization of the KMnO 4 Solution Calculate the molarity of Na 2 C 2 O 4 solution Calculate the molarity of KMnO 4 solution - a ml volume of Na 2 C 2 O 4 solution was used for every run so the average value of the volume of KMnO 4 can be used to find your average [KMnO 4 ] Calculate % deviation of your average value from Part 1 from the class average value

26 Part 2 Determination of Fe 2+ Content and Mass Percent FeSO 4. 7H2 O in an Iron Supplement Pill, Show calculations for one run only. Use your [KMnO 4 ] value. Calculate moles of permanganate used Calculate moles of Fe 2+ Calculate Fe 2+ content in pill in mg Calculate mass of FeSO 4. 7H2 O in pill, in g Calculate mass % of FeSO 4. 7H2 O in pill Write your three values here and then calculate average mass % and ssd of FeSO 4. 7H2 O in pill. x! value sx value ( the ssd ) Additional Calculation Calculate the average mass percent of FeSO 4. 7H2 O using the class average [KMnO 4 ] as follows. Show this calculation. Average Mass % of FeSO 4. 7H2 O x [KMnO 4 ] (class) [KMnO 4 ] (yours)

27 Prelab Exercise Name This exercise reviews the important calculations associated with this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. a. If ml of KMnO 4 solution are required to oxidize ml of M Na 2 C 2 O 4 solution, what is the [KMnO 4 ]? b. A certain brand of iron supplement pill contains iron(ii) sulphate heptahydrate, FeSO 4. 7H2 O, with miscellaneous binders and fillers ml of the KMnO 4 solution used in part a) are needed to oxidize Fe 2+ to Fe 3+ in a g pill. Calculate the mass % of FeSO 4. 7H2 O (molar mass = g mol --1 ) in the pill.

28 Lab Partner Student Name Demonstrator QUALITATIVE ANALYSIS - DATA SHEET Unknown # ion(s) tested reagent(s) added Colour of Unknown Solution observations for known observations for unknown interpretation 1. Ag + HCl 2. NH 4 + NaOH flame red litmus what happens to red litmus? < what happens to red litmus? < 3. Cu 2+ 1) NaOH 1) 2) 1) Zn 2+ 2) NH 3 1) 2) 2) Al 3+ 1) 2) Fe 2+ 1) Fe 3+ 1)

29 ion(s) tested reagent(s) added observations for known observations for unknown inter 4. Na + Li + Cu 2+ wire or wooden stick flame < < < < 5. SO ) BaCl 2 1) 1) 2) HCl 2) 2) 6. NO 3 2 FeSO 4 H 2 SO 4 < < 7. CO 32 2 in large t.t., unknown + HCl heat what happens to limewater? < what happens to limewater? < in other large t.t., limewater

30 ion(s) tested 8. PO 43 2 reagent(s) added (NH 4 ) 6 Mo 7 O 2 2 O HNO 3 heat (if necessary) observations for known observations for unknown interpretation 9. Cl2 AgNO Br2 I2 C 2 HCl 3 + chlorine water colour in the lower layer for Br2 < colour in the lower layer for I2 < colour in the lower layer < Unknown # contains.

31 Pre-Lab Exercise Name This exercise reviews the reactions associated with this experiment. It must be completed before the laboratory period, and handed in before the pre-lab lecture. JoAnn Student has an Unknown solution that contains iron (III) sulphate. For each ion, state the test(s) that will show a positive result. Write the reaction(s) that will occur for each, including states. a. iron (III) ion test number equation b. sulphate ion test number equation

32 Student Name Lab Partner Demonstrator Lab Section Marking scheme Prelab exercise Lab performance Sig figs, units Calculations Graphs Orders Kinetics SUMMARY DATA SHEET Molarity of the stock potassium iodide solution Molarity of the stock potassium bromate solution Molarity of the stock hydrochloric acid solution Integral order of the reaction in [BrO 3 2] is Integral order of the reaction in [H + ] is Integral order of the reaction in [I2] is Overall order of the reaction is Average value of the rate constant k, ssd (with units) at an average room temperature of ssd K Value of the Activation Energy, E a is

33 Table 1: Experimental Data run # temperature C time t s relative rate 1000 / t mol L!1 s!1 [BrO 3 2] in flask mol L!1 [H + ] in flask mol L!1 [I2] in flask mol L!1 stock n/a n/a n/a 1 1 avg of run # t start t finish t avg 9 t start t finish 10 t avg grey boxes must be filled in before leaving the lab

34 WORK SHEETS Preparation of M Na 2 S 2 O 3 solution Stock solution molarity Calculate the volume of stock solution required to prepare ml of M Na 2 S 2 O 3 solution. Determination of the Values for ", $, p and k at room temperature Determination of the value of " run # [BrO 3 2] relative rate run # [BrO 3 2] relative rate Calculate the value of ", the order for [BrO 3 2] Value of " Integral value of " Determination of the value of $, the order for [H + ] run # [H + ] relative rate run # [H + ] relative rate Calculate the value of $ Value of $ Integral value of $

35 Determination of the value of p, the order of the reaction for [I2] Table 2: [I! ] and Relative Rates at Room Temperature run # [I2] in flask log [I2] relative rate mol L2 1 mol L2 1 s2 1 log(rate) Graph log(rate) vs log [I! ] and calculate the slope. If graphing by hand show the slope calculation and points used on your graph. Computer generated graphs must have the equation of the line printed on the graph by the computer. Value of p Integral value of p Determination of the average value of the rate constant, k Use your integral values for ", $ and p to calculate k for each run, equation (1). Table 3: Concentrations, Relative Rates and k at Room Temperature run # [BrO 3 2] mol L2 1 [H + ] mol L2 1 [I2] mol L2 1 relative rate temp. K k

36 Show one sample calculation of the value of k, and the derivation of the units of k here. List your values for k and then use your calculator to find the average and ssd. Average value of k ssd units List your values for the temperature and then use your calculator to find the average and ssd. at an average temperature ssd K Determination of the Activation Energy, E a Use your integral values for ", $ and p to calculate k for each run, equation (1). It is not necessary to show this calculation again (see above). Table 4: k Values at Various Temperatures run # [BrO 3 2] mol L2 1 [H + ] mol L2 1 [I2] mol L2 1 relative rate k temp mol L2 1 s2 1 C

37 Table 5: Arrhenius Data approx temp,. C run # actual temperature, K 1 / T k ln k K room use average 35 Graph ln k vs 1/T and calculate the slope. If graphing by hand show the slope calculation and points used on your graph. Computer generated graphs must have the equation of the line printed on the graph by the computer. Slope of the line is Calculate the value of E a using the slope of your graph Value of the Activation Energy E a is kj mol2 1

38 Prelab Exercise Name This exercise reviews some important calculations associated with this experiment. It must be completed before the laboratory period, and handed in before the prelab lecture begins. a) Which two runs will you use to determine "? b) Which two runs will you use to determine $? c) Which five runs will you use to determine p? d) For the reaction A! Products Calculate the value of k and the correct units. [ A ] rate M 6.25 x 10!6 mol L!1 s! M 2.50 x 10!5 mol L!1 s!1

Chemistry Stoichiometry and Heat Exam (ver.1) Mr. Thaler. Please do not write on this exam. Mark your answers on the scantron only.

Chemistry Stoichiometry and Heat Exam (ver.1) Mr. Thaler. Please do not write on this exam. Mark your answers on the scantron only. 1. Identify from the unbalanced equations below the one that does not represent a redox reaction. a. H 2O 2(aq) + MnO 4 - (aq) O 2(g) + Mn 2+ (aq) b. H 2(g) + N 2(g) NH 3(g) c. NaCl (aq) + AgNO 3(aq) NaNO