Question

3. Propose an experimental procedure to determine the mass percent water in samples of cobalt(II) nitrate. Indicate whether or not it would be possible to infer the molecular formula of an unknown sample of cobalt(II) nitrate from this information.

Explain how the following errors in the experimental procedure would affect the mass percent Co in the analyzed sample of cobalt II nitrate. in particular would the resulting calculating mass percent Co be incorrectly high or low, or the same? explain each answer. A) although a student added 25ml of deionized water to cups A-E he mistakenly added only 20ml of water to cups 1-3. B) a malfunctioning spectrometer consistently read 10% low on every absorbance reading taken in the experiment. C) A student mistakenly weighed anyhrdous CoCl2 instead of CoCl2 * 6H2O, into cups A-E for obtaining the absorbance data for the CoCl2 *6H2O solutions.

A sample of 0.50 g of anhydrous CoCl2(subscript) is dissolved in 25.0 mL of water. Predict the absorbance at 510 nm for this solution

Answer 1