<span>Because
the question is asking moles of NH3, the compound, any subscripts are
irrelevant. It only wants to know how many moles of NH3 molecules, not
individual atoms.
Therefore, we can simply convert to moles. 1.5x10^23/6.022x10^23 = .249 moles of NH3.
(If it were to ask moles of Hydrogen, for example, you would multiply
the answer by 3, because there are 3 atoms of Hydrogen per one molecule
of NH3. But this only asks for moles of the entire compound).
hope you have a great day! :)
</span>
1 mole Hg ---------------- 6.02x10²³ atoms
?? ------------------------- 1.30 x10⁷ atoms
1.30x10⁷ x 1 / 6.02x10²³ =
= 1.30x10⁷ / 6.02x10²³ => 2.159x10⁻¹⁷ moles
hope this helps!
<em>V = 151 mL = 151 cm³</em>
<em>d = 0,789 g/mL = 0,789 g/cm³</em>
--------------------------------------
d = m/V
m = d×V
m = 0,789×151
<u>m = 119,139g</u>
