Silicon nitride is a very hard, high-temperature-resistant c…

Silicon nitride is a very hard, high-temperature-resistant ceramic used as a component of turbine blades in jet engines. Upon reaction of 38.6 g of gaseous nitrogen, N2, with excess silicon, 88.7 g of silicon nitride was obtained according to the balanced equation: 3 Si(s)+ 2 N2(g)⟶Si3N4(s)   What is the percent yield of silicon nitride?  (If you wish, show your work for possible partial credit.)

Silver ions can be precipitated from aqueous solutions by th…

Silver ions can be precipitated from aqueous solutions by the addition of aqueous carbonate:             2  AgNO3 (aq) + Na2CO3 (aq)  →  Ag2CO3(s) + 2 NaNO3 (aq)   Silver carbonate is virtually insoluble in water so that the reaction appears to go to completion. How many grams of Na2CO3 must be added to 25.0 mL of 0.366 M AgNO3 solution to completely precipitate the silver?    (If you wish, show your work for possible partial credit.)