Unit: Stoichiometry "Multi-Step Problems" â WS #3
Directions: Use dimensional analysis to perform the following calculations. Be sure to show all of your work, include your units, and round your answers to the correct number of significant figures. How many formula units of sodium nitrate will react with 20.0 g of calcium carbonate to product sodium carbonate and calcium nitrate according to the following reaction?
2 Na(NO3) + Ca(CO3) à Na2(CO3) + Ca(NO3)2
What volume of oxygen is produced at STP when 6.58 x 1024 molecules of water is decomposed according to the following reaction? 2 H2O à 2 H2 + O2
How many liters of nitrogen gas are needed to react with 90.0 g of potassium at STP in order to produce potassium nitride according to the following reaction? 6 K + N2 à 2 K3N

Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely.analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?

Consider the directing effects of the substituents on salicylamide and predict the possible structures of the iodination products. which do you think will be the major product?

Listenbase your answer to the question on the information below.nuclear radiation is harmful to living cells, particularly to fast-growing cells, such as cancer cells and blood cells. an external beam of the radiation emitted from a radioisotope can be directed on a small area of a person to destroy cancer cells within the body.cobalt-60 is an artificially produced radioisotope that emits gamma rays and beta particles. one hospital keeps a 100.0-gram sample of cobalt-60 in an appropriate, secure storage container for future cancer treatment.which choice represents the correct product for the beta decay of the co-60? fe-60ni-60fe-61ni-61