1-What is the volume in liters of 1.14x10^21 molecules NO2 at STP? 2-What is the mass of 5.07 mole N2?
3-Convert 35.5g NH3 to particles
4-Convert 18.82 L NO gas (STP) to grams:
5-How many molecules of CH4 are in a 24.7g sample?
6-How many atoms of iodine are in 12.75g of CaI2?
7-How many kilograms of lead (IV) nitrate are present in 2.275x1026 formula units?
8-Convert 27.2g Li2S to liters
9-What is the mass in grams of 75.5L of CO2 gas (at STP)?

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.)

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy

Type the letter that represents the correct location for each particle type below. the neutron is found at __ the electron is found at __ the proton is found at __