Of ne
chemistry midterm keview
the
name: _helen
greer
period: 2nd
date: 10-8-19
answer the following questions (using complete sentences) for the midterm review. show work where
needed.
1. five coins from spain were dropped into a graduated cylinder containing 40.50 ml of water. the
volume of the water increased to 41.33 ml. a single coin had a mass of 1.5 grams. what is the
identity of the metal used for the coins?
density of aluminum (al) = 2.7 g/ml
density of copper (cu) = 9.0 g/ml
density of silver (ag) = 10.0 g/ml
density of zinc (zn) = 7.1 g/ml

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.)

Draw the skeletal structures of two different molecules that are each made of 5 carbon atoms and 12 hydrogen atoms.

What is the percentage composition of carbon in the compound ch4