Question 3 (6 points)
Magnesium metal reacts quantitatively with oxygen to give magnesium oxide, MgO. If 5.00 g of Mg and 5.00 g of O2 are allowed to react, what weight of MgO is formed, and what weight of which reactant is left in excess?



Question 4 (6 points)
Mr.T thinks the windows need cleaning (instead of preparing his lesson), (What a mistake!). So instead he starts cleaning his office because it is a disaster. He pulls out the ammonia (NH3) and gets to work. It takes him 5 hours!! During that time he decides to do a little chemistry, because he doesn't want to fall behind. He weighs his bottle of ammonia before (32.3g) and after (30.7g) he cleans. Using this information, he calculates how many atoms are present in the ammonia he used during cleaning.



Question 5 (6 points)
Mr.T keeps getting in trouble for not cleaning his plate completely after supper every night. He argues that it is because there is water-insoluble compounds on his plate so the water won't clean it. Being the cheeky chemist that he is he comes up with a method to make carbon disulfide, a natural solvent for water-insoluble compounds like fats, oils, and waxes. He is going to make millions!! The unbalanced reaction is shown below. When 27.5 g of carbon reacts with 235 g of sulfur dioxide, what mass of carbon disulfide can Mr.T make? Balance the following equation and use it to determine the limiting reagent in order to answer the problem.