Question

PLEASEEEE HELP MEEEEE

Answer 1

Answer:

3.82 x 10²¹ molecules As₂O₃

Explanation:

To find the amount of molecules arsenic (III) oxide (As₂O₃), you need to (1) convert kg to lbs, then (2) convert g As₂O₃ to moles As₂O₃ (via molar mass), and then (3) convert moles to molecules (via Avogadro's number).

1 kilogram = 2.2 lb

Molar Mass (As₂O₃): 2(74.992 g/mol) + 3(15.998 g/mol)

Molar Mass (As₂O₃): 197.978 g/mol

Avogadro's Number:

6.022 x 10²³ molecules = 1 mole

0.0146 g As₂O₃            1 kg                  189 lb
------------------------  x  ---------------  x  ------------------  x   ................
         1 kg                     2.2 lb          

       1 mole                6.022 x 10²³ molecules
x  ------------------  x  ---------------------------------------  = 3.82 x 10²¹ molecules As₂O₃
      197.978 g                        1 mole

Answer 2

3.82 x10^21 molecules As2O3