A fictitious element X is composed of 10.0% of the isotope X-55, 20.0% of the isotope X-56, and 70.0% of X-57. Calculate the average atomic mass of element X

219 grams of iron (iii) oxide reacts with excess carbon according to the reaction equation shown below. fe2o3 + c → fe + co2 after a scientist performs the chemical reaction they find the actual yield of iron to be 57.4 grams. calculate the percent yield of this chemical reaction.

Which is an example of the practical pursuit of alchemy? a. forming perfect substances. b. transforming base metals. c. developing metalworking techniques. d. linking spiritual characteristics with material substances.

Nitrogen dioxide decomposes according to the reaction 2 no2(g) ⇌ 2 no(g) + o2(g) where kp = 4.48 × 10−13 at a certain temperature. if 0.70 atm of no2 is added to a container and allowed to come to equilibrium, what are the equilibrium partial pressures of no(g) and o2(g)