How are N 2 , CN − , and CS alike? Mark all that are true. All three chemical species have the same overall formal charge. the same number of valence electrons. a bond order of 3. a double bond. a σ p as the highest occupied molecular orbital (HOMO). a σ ∗ p HOMO. a π p as the lowest unoccupied molecular orbital (LUMO). a π ∗ p LUMO. completely filled degenerate π p orbitals (2 e − in each orbital). singly filled degenerate π p orbitals (1 e − in each orbital). singly filled degenerate π ∗ p orbitals (1 e − in each orbital). empty degenerate π ∗ p orbitals (no e − in orbitals).

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Agas is contained in a thick walled balloon when the pressure changes from 1.21 atm to 2.52 the volume changes from 3.75 l to 1.72 l and the temperature change from 293k to blank k

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.)