Sam conducts an experiment at STP. He has 21 different gases in a cylinder and each exerts the same partial pressure. What is the partial pressure exerted by each of the gases? (in two significant figures)

The answer will be c

Idon't mean to be a smart alec, length of atoms' bonds is the simplest way to define it.

Homogeneoushoped i

Pcl5 + 4 h2o = h3po4 + 5 hclthe ratio is 1: 5 for  pcl  and hcl, 1 mole of pcl produces 5 moles of hclmolecular weight of pcl5 is: 31 + (5 x 35.5) = 208.5above we have 75.5 / 208.5 = 0.36 moles so this will produce0.36 x 5 = 1.81 moles of hcl.