After leaving the cockroaches in their metabolic chamber for one hour the gases in the chamber was measured. the fraction of oxygen in the chamber was 0.18. what is the metabolic rate of the cockroaches in ml o2/hr? assume room air is 21% o2 and chamber volume = 500ml).

a. 22.5
b. 0.135
c. 0.225
d. 13.5

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution?

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.)

8) warming your hands by a fire is an example if which heat transfer? a. conduction b. convection c. radiation d. none of these