1. antoine lavoisier, a french scientist, established which principle? a. mercury and oxygen are nonreactive. b. an open system is required to observe changes in mass. c. the total mass of the products of a reaction is always slightly more than the total mass of the reactants. d. the total mass of the products of a reaction is equal to the total mass of the reactants.

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.)

How many liters of oxygen gas, at standardtemperature and pressure, will react with 35.8 grams ofiron metal? 4 fe (s) + 3 o2 (g) → 2 fe2o3 (s)

Can anyone answer these questions? ? i need it before 1: 00pm today