A hot air balloon is filled with 3L of air and it exerts a pressure of 250kPa 25 points against the walls of the balloon. When air is released, the pressure of the
hot air balloon drops to 150kPa. Find the final Volume.

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.)

Which element is the least metallic between cadmium, silver, zinc, or iron?

Exit what is the density of an object having a mass of 5.0 g and a volume of 45.0 cm3?