Which is a characteristic of chemical equilibrium but not physical equilibrium? a) the changes occur at the same rate. b) only chemical equilibrium occurs in a closed system. c) the reactants and products are different substances. d) the reactants and products are the same substances.

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.)

An unsaturated hydrocarbon is a hydrogen-carbon compound with a. a network solid structure b. single bonds c. single bonds in a branched-chain structure d. double or triple bonds

If 2 molecules of one reactant combine with 3 molecules of another to produce 5 molecules of a product, then what is the representation of the reaction?