<span>Answer: 100 ml
</span>
<span>Explanation:
1) Convert 1.38 g of Fe₂S₃ into number of moles, n
</span>i) Formula: n = mass in grass / molar mass
<span>
ii) molar mass of </span><span>Fe₂S₃ =2 x 55.8 g/mol + 3 x 32.1 g/mol = 207.9 g/mol
</span>
iii) n = 1.38 g / 207.9 g/mol = 0.00664 moles of <span>Fe₂S₃
</span>
<span>2) Use the percent yield to calculate the theoretical amount:
</span>
<span>65% = 0.65 = actual yield/ theoretical yield =>
</span>theoretical yield = actual yield / 0.65 = 0.00664 moles / 0.65 = 0.010 mol <span>Fe₂S₃</span><span>
3) Chemical equation:
</span>
<span> 3 Na₂S(aq) + 2 FeCl₃(aq) → Fe₂S₃(s) + 6 NaCl(aq)
4) Stoichiometrical mole ratios:
</span>
<span>3 mol Na₂S : 2 mol FeCl₃ : 1 mol Fe₂S₃ : 6 mol NaCl
5) Proportionality:
</span>2moles FeCl₃ / 1 mol Fe₂S₃ = x / 0.010 mol Fe₂S₃
<span>
=> x = 0.020 mol FeCl₃
6) convert 0.020 mol to volume
</span>
<span>i) Molarity formula: M = n / V
</span>
<span>ii) V = n / M = 0.020 mol / 0.2 M = 0.1 liter = 100 ml
</span>
Answer: 1. The empirical formula is 
2. The molecular formula is
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of P = 37.32 g
Mass of N = 16.88 g
Mass of F = 45.79 g
Step 1 : convert given masses into moles.
Moles of P =
Moles of N =
Moles of F =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For P = 
For N =
For F =
The ratio of P: N: F= 1: 1: 2
Hence the empirical formula is
The empirical weight of = 1(31)+1(14)+2(19)= 82.98 g.
The molecular weight = 82.98 g/mole
Now we have to calculate the molecular formula.
The molecular formula will be=
Carbon and silicon have same number of valance electrons which is 4 electrons
Now, Barium is a 2nd group element. So, it has two valance electrons.
Silicon is a 16th group element and it has 4 valance electrons as does the carbon. This is because they both stay in the same group in the periodic table.
Neon is a noble gas which has 8 valance electrons and stays in the 18th group.
Therefore, carbon and silicon have same number of valance electrons which is 4 electrons.
<h3>What are Valence electrons ?</h3>
The electrons in an atom's outermost shell, or energy level, are called valence electrons. For instance, the valence electrons of oxygen are six, with two in the 2s subshell and four in the 2p subshell.
- The number of valence electrons for neutral atoms is the same as the number of the atom's main group. A periodic table element's column can be used to determine its main group number. For instance, carbon, which belongs to group 4, has four valence electrons. Group 6 oxygen contains six valence electrons.
Learn more about Valence electrons here:
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Answer:
The suns mass effects the solar system by having a great gravitational pull. This cause the success rate to grow lower each time.
