Answer:
molecular weight (Mb) = 0.42 g/mol
Explanation:
mass sample (solute) (wb) = 58.125 g
mass sln = 750.0 g = mass solute + mass solvent
∴ solute (b) unknown nonelectrolyte compound
∴ solvent (a): water
⇒ mb = mol solute/Kg solvent (nb/wa)
boiling point:
- ΔT = K*mb = 100.220°C ≅ 373.22 K
∴ K water = 1.86 K.Kg/mol
⇒ Mb = ? (molecular weight) (wb/nb)
⇒ mb = ΔT / K
⇒ mb = (373.22 K) / (1.86 K.Kg/mol)
⇒ mb = 200.656 mol/Kg
∴ mass solvent = 750.0 g - 58.125 g = 691.875 g = 0.692 Kg
moles solute:
⇒ nb = (200.656 mol/Kg)*(0.692 Kg) = 138.83 mol solute
molecular weight:
⇒ Mb = (58.125 g)/(138.83 mol) = 0.42 g/mol
To answer the question above, we take note first that every mole of PCl₃ contains 3 atoms of Cl. First, we divide the given number by 3.
3.68 x 10²⁵ / 3 = 1.227 x 10²⁵
Then, we divide the answer by the Avogadro's number which is equal to 6.022 x 10²³. That is,
1.227 x 10²⁵ / (6.022 x 10²³) = 20.37
Thus, there are 20.37 mol of PCl₃.
The two reasons why the UK government is
encouraging citizens to recycle iron and steel is:
<span><span>
1. </span>The environment. Every machinery and device the industries makes
which includes, infrastructures, mega structures to micro devices. Iron and
steel is used. Reducing the extraction of ore and creating steel saves the
environment, reduces mining.</span>
<span><span>
2. </span>Economic reasons. When the ore mining and steel making is reduced
in activity, the government won’t just be able to save the environment but it
also save funds for other purposes.</span>
<span>The formula given for it is
moles = given wt/mol.Wt
Mol.wt of nacl
nacl=23+35.5
=58.5 gm
Moles = 29/58.5
= 0.495
~ 0.15 moles </span>
