Answer:
5.3 × 10⁻¹⁷ mol·L⁻¹
Explanation:
Let <em>s</em> = the molar solubility.
Cu₂S(s) ⇌ 2Cu⁺(aq) + S²⁻(aq); K_{sp} = 6.1 × 10⁻⁴⁹
E/mol·L⁻¹: 2<em>s</em> <em>s
</em>
K_{sp} =[Cu⁺]²[S²⁻] = (2<em>s</em>)²×<em>s</em> = 4s^3 = 6.1 × 10⁻⁴⁹

![s = \sqrt[3]{1.52 \times 10^{-49}} \text{ mol/L} = 5.3 \times 10^{-17} \text{ mol/L}](https://tex.z-dn.net/?f=s%20%3D%20%5Csqrt%5B3%5D%7B1.52%20%5Ctimes%2010%5E%7B-49%7D%7D%20%5Ctext%7B%20mol%2FL%7D%20%3D%205.3%20%5Ctimes%2010%5E%7B-17%7D%20%5Ctext%7B%20mol%2FL%7D)
Based on experiment 1:
Mass of Hg = 1.00 g
Mass of sulfide = 1.16 g
Mass of sulfur = 1.16 - 1.00 = 0.16 g
# moles of Hg = 1 g/200 gmol-1 = 0.005 moles
# moles of S = 0.16/32 gmol-1 = 0.005 moles
The Hg:S ratio is 1:1, hence the sulfide is HgS
Based on experiment 2:
Mass of Hg taken = 1.56 g
# moles of Hg = 1.56/200 = 0.0078
Mass of S taken = 1.02 g
# moles of S = 1.02/32 = 0.0319
Hence the limiting reagent is Hg
# moles of Hg reacted = # moles of HgS formed = 0.0078 moles
Molar mass of HgS = 232 g/mol
Therefore, mass of HgS formed = 0.0078 * 232 = 1.809 g = 1.81 g
Explanation:
Below is an attachment containing the solution.
Number of atoms in 1.4 mol of Phosphorus trifluoride (PF₃) : 8.428 x 10²³
<h3>Further explanation </h3>
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
1.4 mol of Phosphorus trifluoride (PF₃), number of atoms :

<span>Uranium-236 is intermediate nuclei. created by fusion reactions an unstable isotope of uranium created from four hydrogen atoms used in the H-bomb.
Following is the reaction involved in above process:
</span>

+

→

→

+

+ 3

<span> + 177 MeV
</span>
Here,

= Fission material,

= projectile,

= intermediate nuclei,

and

= Fission product