How many seconds long is this chemistry class if it lasts 40.0 minutes?

How many mmols of tris-hcl are there in 100 ml of a 100 mm tris-hcl buffer solution at ph 8.1? note that the 100 mm refers to the sum of tris and tris-hcl concentrations?

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)

Which sentence from holes contains an implied personality trait? stanley and his parents had tried to pretend that he was just going away to camp for a while, just like rich kids do. he'd just been in the wrong place at the wrong time. stanley felt somewhat dazed as the guard unlocked his handcuffs and led him off the bus. stanley nodded to show he understood