CHY203 -X-Ray Powder Diffractometry lab report

Department of Chemical Engineering X-Ray Powder Diffractometry Student name: Student number: Group 2 CHY203, Section 02 February 12, 2013 Instructor: David Naranjit TA: Justin Report Form for X-Ray Powder Difffractometry Silica Standard: Standard d (?) I/I1 Position (2) d (?) Experimental % Deviation in d Intensity (counts) I/I1 3.343 100 31.00 3.35 0.21 10871 100 4.26 35 24.250 4.26 0 2778.0 25.00 1.817 17 58.950 1.82 0.17 1116.0 9.70 1.541 15 46.150 2.28 47.96 793.0 6.85 2.458 12 42.650 2.46 0.08 765.0 6.10 2.282 12 70.90 1.54 -32.52 763.0 4.76 2.128 9 81.350 1.37 -35.62 751.0 6.25 1.372 9 81.100 1.38 0.58 619.0 5.05 Effect of Grinding: Standard d (?) I/I1 Ground d (?) I/I1 Unground d (?) I/I1 2.82 100 2.84 100 2.82 100 1.99 55 2.00 11.43 2.79 9.70 1.63 15 1.41 10.37 1.99 9.22 3.26 13 1.41 2.30 1.63 5.65 1.26 11 3.28 2.18 1.41 5.65 Unknown Sample Three largest peaks Secondary peaks (for confirmation) Expt. Counts 9326.0 4207.0 1156.0 770.0 338.0 164.0 94.0 Expt. 2 45.45 66.20 83.950 84.2 37.2 78.85 66.9 Expt. d (?) 2.32 1.64 1.34 1.34 2.81 1.41 1.62 Std. d (?) 2.3166 1.6380 1.377 1.0359 1.1584 1.3968 1.0630 1021976138766SAMPLE NO. 2 2026024159460SAMPLE IDENTIFICATION: Sodium Fluoride NaF 1497217151504CRYSTAL PLHASE: White Solid cubic Octahedral Calculations for X-Ray Diffractometry based on tables 1, 2 and 3 on the attached document: Intensity of Silica Standard The intensity of peaks Cpeak was calculated from as shown below: For position (2) of 31 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (11093- 407) / (11093-407)*100 = 100 For position (2) of 24.25 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (3040- 353) / (11093-353)*100 = 25.00 For position (2) of 58.95 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (1187- 123) / (11093-123)*100 = 9.70 For position (2) of 46.15 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (890- 140) / (11093-140)*100 = 6.85 For position (2) of 42.65 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (883- 220) / (11093-220)*100 = 6.10 For position (2) of 70.90 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (833- 320) / (11093-320)*100 = 4.76 For position (2) of 81.35 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (823- 137) / (11093-137) * 100 = 6.26 For position (2) of 81.10 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (690- 137) / (11093-137)*100 = 5.05 The experimental percentage deviation in d spacing (Ao ) for eight larges quartz peaks of Silica Standard that was calculated as shown for peak #1 below: Experimental % Deviation in d= [(d experimental-d standard) /d standard] x100% = [3.35-3.343/3.343]*100% = 0.21% Effect of Grinding: Intensity of NaCl Intensity of Ground NaCl For position (2) of 36.75 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (7743- 367) / (7743-367) * 100 = 100 For position (2) of 53.10 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (1237- 397) / (7743-397) * 100 = 11.43 For position (2) of 78.55 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (1063- 290) / (7743-290) * 100 = 10.37 For position (2) of 66.4 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (283- 107) / (7743-107) * 100 = 2.30 For position (2) of 31.7 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (413- 250) / (7743-250) * 100 = 2.18 Intensity of Unground NaCl For position (2) of 37.0 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (3837- 303) / (3837-303) * 100 = 100 For position (2) of 53.4 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (487- 127) / (3837-127) * 100 = 9.70 For position (2) of 66.70 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (460- 117) / (3837-117) * 100 = 9.22 For position (2) of 30.35 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (327- 117) / (3837-117) * 100 = 5.65 For position (2) of 30.35 36766530543500 Cpeak – Cbg I/I1= X100 C100 - Cbg Peak = (327- 117) / (3837-117) * 100 = 5.65 Graph1. X-Ray Intensity of Standard Quartz and 2 Degrees Graph2. Grounded Salt NaCl X-Ray Intensity and the 2 Degrees Graph 3.Ungrounded NaCl X-Ray intensity and the 2 Degrees Graph4. NaF X-Ray Intensity and 2 Degrees Lab Questions: Q1) According to your quartz diffractogram. Is the diffractometer properly aligned? According to the Silica Standard table spacing in d (Ao), the diffractometer is absolutely properly aligned. For example, the experimental measured distance of position 31 (2) was 3.35 which is almost close to the standard distance 3.342 of highest peak. Also, the d spacing for the second highest peak of the quartz was 4.26 that perfectly close to the standard distance 4.26 as shown in the table of the silica standard. However, the Experimental percentage deviation in the d spacing of the highest peak was 0.21% which confirmed that the diffractometer was aligned properly. Q2) what might account for the difference between the relative intensities that you obtained from your quartz diffractogram and the standard values? The difference between the measured intensities that obtained experimentally from the standard value of the quartz diffractogram is due to some experiment errors. Firstly, the sample was not aligned properly on the quartz rectangle metal holder which cause beams that were reflected from the planes measured only a small value of intensity comparing with the standard one. Also, it might difference because the quartz standard was not placed properly and gently into sample holder clip which cause the diffractmetes to produce different singles for the sample and hence different scanned angles than the standard one. Q3) Which NaCl sample, ground or unground, behaves more like the standard? The NaCl ground sample behaves more like the standard sample than the unground. Ground NaCl for the highest peak of d spacing was 2.84 which relatively close to the standard value 2.82. Also, the intensity of the ground salt that was determined experimentally was fairly close to the standard one. For example, the x-Ray intensity of the measured ground salt was 10.37 whereas the standard intensity was 15. However, the measured intensity of the unground NaCl for was 5.65 where the standard intensity is 13 which is way far from the standard value. Thus, that confirms that the ground NaCl acts more like the standard sample than the unground NaCl. Q4) the x-ray intensities for this experiment are very low. The y-axis on your diffractogram represents the number of photons that struck the detector during the collection interval. The energy of a single photon is given by the equation E=hc/, where h is Planck’s constant, c is the speed of light, and is the wavelength of the x-radiation (1.79x10-10 m). Determine the power (in watts) of the largest peak in your ground NaCl diffractogram. For one x-ray counts (photon detected): The Planck’s constant 1 h = 6.62068x10-34 m2 kg/s Speed of light 2 c= 2.9979x108 m/s = 1.79x10-10 m E=hc/ = (6.62068x10-34 m2 kg/s * 2.9979x108 m/s)/ 1.79x10-10 m = 1.1088x10-15 J (Joules) For largest peak of Ground NaCl : Larges peak = 7743 counts E= (1.1088x10-15 J) * (7743 counts) = 8.5854x10-12 J P= (8.5854x10-12 J- 12 J)/0.4 sec = 2.146x10-11 Watts References: Stephen Van Dulken (author) ‘Planck Constant’, 3 February 2013, http://en.wikipedia.org/wiki/Planck_constant Soloway, S., Wilen, ‘Speed of light’, 13 January 2013 http://en.wikipedia.org/wiki/Speed_of_light Instrumental Method of analysis Lab Manual- X-Ray Diffractions