A 250mL sample of air at STP contains approximately 52.5mL of O2. What is the percentage of oxygen in the air

0.09 moles of sodium sulfate in 12 ml of solution

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both

You are attempting to recrystallize a crude product mixture. you add the appropriate amount of hot solvent and are allowing the solution to slowly cool to room temperature. however, at room temperature no crystals have appeared, which of the following methods should be used to induce crystallization? choose all correct answers. a) place the flask in an ice bath. b) swirl the contents of the flask. c) add a small seed crystal of the desired product. d) scratch the inside of the glassware using a stir rod. it can be multiple choices