I have asked before but I do not know how to do the least squares method. Can so

Question

I have asked before but I do not know how to do the least squares method. Can someone explain please.

To measure Ca in breakfast cereal, 0.521 6 g of crushed Cheerios was ashed in a crucible at 600C in air for 2 h.32 The residue was dissolved in 6 M HCl, quantitatively transferred to a volumetric flask, and diluted to 100.0 mL. Then 5.00-mL aliquots were transferred to 50-mL volumetric flasks. Each was treated with standard (containing 20 micrograms/ml ), diluted to volume with H2O , and analyzed by flame atomic absorption. Construct a standard addition graph and use the method of least squares to find the x-intercept and its uncertainty. Find wt% Ca in Cheerios and its uncertainty.

Ca2+ Standard Absorbance (mL) 0 0.151 1 0.185 3 247 5 0.3 8 0.388 10 0.445 15 0.572 20 0.723

Explanation / Answer

Final set of parameters Asymptotic Standard Error

======================= ==========================

m = 0.0281943 +/- 0.0003091 (1.096%)

c = 0.157869 +/- 0.003137 (1.987%)

correlation matrix of the fit parameters:

m c

m 1.000

c -0.764 1.000   

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.