A) they (somewhat foolishly) only did one experiment: 1) they pipetted 25.0 ml into a pre-weighed erlenmeyer flask (mass flask plus stopper = 56.632 g) and obtained the mass of the flask, stopper, and liquid as 79.524 g. the stencil on the side of the pipet states the uncertainty as± 0.05 ml and the documentation for the analytical balance says its uncertainty is ± 1 mg. calculate the density of the liquid and either the relative uncertainty or the absolute uncertainty in the density obtained

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

What effect might melting sea ice have for people who live in coastal areas?

How many liters of oxygen gas, at standard temperature and pressure, will react with 35.8 grams of iron metal? 4 fe (s) + 3 o₂ (g) → 2 fe₂o₃ (s)