Which of the following facts did Dalton realize? a. Two different elements can only form one type of compound. b. Each compound contains a fixed ratio of atoms. c. Atoms of the same element can have different masses.

it's all four options.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.

the answer is d. 74.02