I assume you're talking about fluorine. Fluorine is in the halogen family and it belongs to group number 17.
Answer:
<h2>0.5 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>0.5 moles </h3>
Hope this helps you
Answer: XF8
Explanation:
Empirical Formular shows the simplest ratio of elements in a compound.
Xe = 46.3% F = 53.7%
Divide the percentage composition of each element by the atomic mass.
Xe = 46.3/ 131.3 F= 53.7/ 19
= 0.353( approx) = 2.826 (approx)
Divide through with the smallest of the answers gotten in previous step.
Xe = 0.353 / 0.353 F = 2.826/ 0.353
= 1 = 8.0
Empirical formular = XF8
Multiply,
moles * molar mass = mass
Answer:
ΔHr = -86.73 kJ/mol
Explanation:
Using Hess's law, you can calculate ΔH of any reaction using ΔH°f of products and reactants involed in the reaction.
<em>Hess law: ∑nΔH°f products - ∑nΔH°f reactants = ΔHr</em>
<em>-Where n are moles of reaction-</em>
For the reaction:
Fe³⁺(aq) + 3 OH⁻(aq) → Fe(OH)₃(s)
Hess law is:
ΔHr = ΔH°f Fe(OH)₃ - ΔH°f Fe³⁺ - 3×ΔH°f OH⁻
Where:
ΔH°f Fe(OH)₃: −824.25 kJ/mol
ΔH°f Fe³⁺: −47.7 kJ/mol
ΔH°f OH⁻: −229.94 kJ/mol
Replacing:
ΔHr = −824.25 kJ/mol - (−47.7 kJ/mol) - (3×-229.94 kJ/mol)
<em>ΔHr = -86.73 kJ/mol</em>
