2a + 3 b right arrow 4 c + 5 d in the first 120 s of the given reaction, 0.500 moles of b disappear. in that time period, what is the rate of appearance of c in mol/min?

So number of moles C = 0.5 mole B ( 4 mole c / 3 moles B)

Number of moles C = 0.67 moles C appeared in 120 s

So mol/min = 0.67 moles / 2 min = 0.33 moles C / min

c is the answer because when something is left after something evaporates that shows the chemical change.

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explanation: