Empirical formula Lab
background [prelab assignment (20 points); due at the beginning of the lab]
identify the metal in the compound, i.e. Cu+ or Cu++
determine the empirical formula of the sample (a hydrated metal chloride)
~ 1.5 g of hydrated copper chloride
balance; watch glass; flask; test tube holder
water; 25 mL 1.0 M silver nitrate (forms a precipitate, AgCl, with any chloride containing soluble ionic compound; assume that sliver nitrate is the excess reactant)
filter paper / funnel
methods / data analysis
gentle heating of chemical (i.e. form brownish solid, not blackish liquid); otherwise, could produce chlorine gas
Content of lab report [30 points]
data analysis [15 points]
data table of your experimental measurements
determination of the compound's empirical formula - based on your group's data (show your work)
error analysis: no effect ? underestimate ? overestimate ? [15 points]
effect of insufficiently heating the hydrated sample on the determination of the sample's water content. justify your response.
effect of overheating the hydrated sample on the determination of the samples' chloride content. justify your response.
effect of copper chloride versus silver nitrate being the limiting reactant on the determination of the sample's chloride content and subsequent determination of its copper content. justify your response.
effect of insufficient drying the silver chloride on the determination of the sample's chloride content and subsequent determination of its copper content (assume the filter paper is completely dried) justify your answer.
the (hydrated copper chloride and / or the dehydrated copper chloride) sample may be "hygroscopic" - what is the effect on your results ? be specific & justify your response; include a definition of the term; there are 3 cases to describe.
lab activity source (examples): site 1 [access 4 / 2009]
heat suspension rationale