10) Which gas sample at STP has the same number of molecules as a 2.0 Liter sample of Cl2 (g) at STP?
a) 1.0 L of H2 (g) b) 2.0 L of He
c) 3.0 L of NH3 d) 4.0 L of O2 (g)
11) 0.500 atm of NH3 gas is placed in a 12.0 L rigid container which was measured
at standard temperature.
a) Determine the mass of NH3 gas in this container in grams.

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.)