Using incorrect concentrations. If your vitamin C standard solution is too concentrated or your iodine titration solution is too diluted, or your starch indicator solution is not between 0.5 to 1.0%, it may require much more than 50 mL of iodine solution to titrate the standard solution and/or orange juice.
The following summarizes some common causes of fatigue but is not meant to be comprehensive: Metabolic/endocrine: anemia; hypothyroidism; diabetes; electrolyte abnormalities; kidney disease; liver disease; Cushing's disease.
Diseases Causing Extreme Fatigue & Weakness. Many diseases can cause extreme fatigue and weakness. According to MedlinePlus, a service of the U.S. National Library of Medicine and the National Institutes of Health, fatigue is a feeling of weariness, tiredness or a lack of energy, and fatigue is different from drowsiness.