Sodium Phosphate Monobasic Synthesis Lab Report

In experiment 3.1.We set up and calibrate the spectronic 20 first since it takes time to be ready to use so, we turned the spectronic 20 to warm up for at least 15 minutes, set wavelength to 360 while no test tube in it. Also, we set the filter lever in order to match the wavelength range, and then set the transmittance to 0%, then we changed the mode to absorbance. After we labeled two test tubes which were #5 and #10, we inserted water first to set 0 absorbance, then we used #5 sample to read it and record absorbance. At this time, we set spectronic 20 again for sample #10 by taking sample #5 out and inserted water to set transmittance to 0 then we took the water sample out and inserted #10 sample to read it and record the results. We measured the absorbance of most highly colored tube at wavelength of 360-500nm by using 20nm intervals. Then we repeated the absorbance measurement with less colored tube after we adjusted it to 0 absorbance (100%T) at each wavelength, in order to determine most reasonable wavelength which was 460nm for 2-3 experiment.
We used 250 ml of 0.1M Sodium phosphate Monobasic, which equal 2.9995g, we added it to the 250ml beaker and added 50.0ml of water to dissolve it. On the same time, we prepared 250ml of 0.1 Sodium phosphate Dibasic, which equal to 3.549g; we added 50.0ml of water to be dissolved. We made these two solutions in order to get their PH. We started with PH 6.0 buffer from Sodium phosphate monobasic solution, we added 50ml of Sodium phosphate Dibasic to 250ml beaker, placed PH probe, then added solution Sodium phosphate monobasic until PH was between (5.9-6.1), and we called it solution