30. Solving a chemistry problem

9. A solution of analgin for injection 50% was analyzed in order to assess the correctness of the method of analysis by the method of iodimetric titration for the content of analgin and found in five parallel determinations the mass m of analgin in 1 ml of solution, equal, g: 0.497; 0.499; 0.500; 0.502; 0.503. The true content of analgin in 1 ml of solution (introduced into the preparation) is Mu = 0.500 g. Describe the analysis method in terms of reproducibility (calculating the confidence interval m ± Δm and the relative error ε in determining the average result) and correctness (calculating the systematic error of the analysis, if any ) at a confidence level Р=0.95. Answer: m±Δm=0.500±0.003 g; ε=0.6%. The true value of 0.500 g is within the confidence interval. There is no systematic error. The technique gives correct results.