Question: How do you know if a reaction is endothermic?

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.

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.)

Chris is about to do an experiment to measure the density of water at several temperatures. his teacher has him prepare and sign a safety contract before beginning the experiment. which term is mostlikely part of the safety contract