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.
Cancer has many factors that causes excessive fatigue, such as: weight loss, breakdown of the tissues with release of energy, hormonal imbalances, depression and anxiety, which by themselves can cause fatigue, sleep disruption can also lead to sleepiness and fatigue, cancer treatments, such as radiation and chemotherapy can also cause extreme fatigue.