Pls find the solution for number a All glassware must be very clean for this lab
ID: 530236 • Letter: P
Question
Pls find the solution for number a All glassware must be very clean for this lab exercise. It should be washed, rinsed with tap water, rinsed twice with 0.1 M HCl, and then rinsed with distilled water. Obtain a small amount of the calcium stock solution from the lab instructor. The concentration of this solution is 500 mug/mL. Using distilled water and volumetric flasks, make standard solutions with these concentrations: a) 100 mug Ca/mL b) 50 mug Ca/mL c) 30 mug Ca/mL d) 20 mug Ca/mL e) 10 mug Ca/mL f) 5 mug Ca/mL Since these solutions will form the basis for your calibration curve, it is important that they be made as accurately as possible. Take all of your known's and unknowns to the Instrument Room, R 207 for analysis. Your instructor or lab tech will show you how to use the instrument. For detailed direction on the AA instrument use, see the Chemistry Department web site, mvw.pierce.ctc.edu/go/chemistry, then select lab equipment web site, and AA Instructions. Show your calculations for making the standard solutions Make a graph of concentration vs absorbance using "Logger Pro" or another computerized graphing program. Determine the concentrations of each of the unknowns in micrograms per ml. Show your calculations if you diluted your samples.Explanation / Answer
Preparation of standard solutions
using,
volume of stock to be taken = final concentration x final volume/initial concentration
let's assume the final volume in each case be 100 ml
a) 100 ug/ml
= 100 ug/ml x 100 ml/500 ug/ml
= 20 ml
So 20 ml of 500 ug/ml stock diluted with 80 ml distilled water would give 100 ug/ml solution
b) 50 ug/ml
= 50 ug/ml x 100 ml/500 ug/ml
= 10 ml
So 10 ml of 500 ug/ml stock diluted with 90 ml distilled water would give 50 ug/ml solution
c) 30 ug/ml
= 30 ug/ml x 100 ml/500 ug/ml
= 6 ml
So 6 ml of 500 ug/ml stock diluted with 94 ml distilled water would give 30 ug/ml solution
d) 20 ug/ml
= 20 ug/ml x 100 ml/500 ug/ml
= 4 ml
So 4 ml of 500 ug/ml stock diluted with 96 ml distilled water would give 20 ug/ml solution
e) 10 ug/ml
= 10 ug/ml x 100 ml/500 ug/ml
= 2 ml
So 2 ml of 500 ug/ml stock diluted with 98 ml distilled water would give 10 ug/ml solution
f) 5 ug/ml
= 5 ug/ml x 100 ml/500 ug/ml
= 1 ml
So 1 ml of 500 ug/ml stock diluted with 99 ml distilled water would give 5 ug/ml solution