Determine the number of moles of compound in each of the following compounds?
4.50g h2o

471.6g ba(oh)2
129.68g fe3(po4)2

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days