Which type of reaction involves one element replacing another element in a compound
2 answers:
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0.042 moles of Hydrogen evolved
<h3>Further explanation</h3>Given
I = 1.5 A
t = 1.5 hr = 5400 s
Required
Number of Hydrogen evolved
Solution
Electrolysis of water ⇒ decomposition reaction of water into Oxygen and Hydrogen gas.
Cathode(reduction-negative pole) : 2H₂O(l)+2e⁻ ⇒ H₂(g)+2OH⁻(aq)
Anode(oxidation-positive pole) : 2H₂O(l)⇒O₂(g)+4H⁻(aq)+4e⁻
Total reaction : 2H₂O(l)⇒2H₂(g)+O₂(g)
So at the cathode H₂ gas is produced
Faraday : 1 mole of electrons (e⁻) contains a charge of 96,500 C
Q = i.t
Q = 1.5 x 5400
Q = 8100 C
mol e⁻ = 8100 : 96500 = 0.084
From equation at cathode , mol ratio e⁻ : H₂ = 2 : 1, so mol H₂ = 0.042
Answer:
Mass fraction = 0.08004
Mole fraction = 0.0377
Explanation:
Given, Mass of NaOH = 8.70 g
Mass of solution = 8.70 + 100 g = 108.70 g
= 0.08004
Molar mass of NaOH = 39.997 g/mol
The formula for the calculation of moles is shown below:
Thus,
Given, Mass of water = 100 g
Molar mass of water = 18.0153 g/mol
The formula for the calculation of moles is shown below:
Thus,
So, according to definition of mole fraction: