How many oxygen atoms are there in 170 grams of cesium phosphate?

Question

The answer key says 6.43 x 10^23 atoms but I keep getting 8.29 x10^23, am i doing anything wrong here?

Answer 1

okay you start out with 170 g of cesium phosphate, and you need to first convert to moles of cesium phosphate
so 170 g x molar mass ( 1/3(132.90)+30.973+4(16.00) or 1/493.673) =0.3443575 moles of cesium phosphate

and so you know there are 6.022x10^23 molecules per mole so multiply moles by 6.022x10^23 and get 2.073720864 x 10^23 molecules, and you have 4 atoms of O per molecule
so multiply 2.073720864 x 10^23 by 4 and get

8.294883455 x 10^23 atoms of O.

so um. in answering your question. no i don't think you're getting anything wrong. i think it might be a typo? you should probably ask your teacher if it's a typo or anything. because I think it's 8.29 x 10^23.

:) i think it's a typo.

Answer 2

3*133 + 31 + 4*16 = 494 g/mol
N(O) = 4(170 g/494 g/mol)(6.022*10^23)
N(O) ≈ 8.29*10^23
It looks like the person who calculated your answer key used PO3 instead of PO4 for phosphate.

Answer 3

6.43x10^23 would be the correct answer is the question asked for the oxygen atoms in cesium phosphite (Ce3PO3).