Question

2. A student wants to determine the concentration of phosphate ions in 10.0 mL of water. He prepares 4 solutions that contain a known amount of phosphate as shown in Table 1. He mixes these solutions plus the sample of water with H2SO4, ammonium molybdate and ANSA. The results are shown in Figure 1 below. The final volumes of all tubes are identical. TABLE 1 Solution # Amount of Phosphate (umoles) 0 20.0 50.0 80.0 Solution #1 Solution #2 Solution #3 Solution #4 Sample of drinking water Figure 1: The phosphate standard solutions and the sample of drinking water after the addition of H2SO4, ammonium molybdate and ANSA a) How many umol of phosphate ions are present in the drinking water sample? (Show calculations.) umount of phosphate will need to be approximated if the intensity of the sample is between the inters two standards. Because the final volumes are all identical, an identical intensity indicates and umoles. b) What is the concentration in micromolarity of the phosphate in the wa

Answer 1

Answer :- Page No - o Given that, (a) so umol of phosphate ions are presented in drinking water sample. I since the color of the reference sample #3 and color of the deinking watu sample are same, we can approximate the concentration of the phosphate concentration . luthermore, volume of the final solution is same. - Hence, the concentration deinking water sample is equal to the concentration Sample #3 solution. (6) We have come drinking watu solution containing 50 umol of phosphate ions. . We need to calculate the elroll; is micro molaity no. el moles ! vol in L = 50 u mol/0.010 1 - 5000 umol/L.