In an electrochemical cell, electrons travel in which direction? * (a) from the anode to the cathode through the external circui
1 answer:
You might be interested in
Answer:
The change in the pH (ΔpH) is 2,17
Explanation:
The reaction:
CH₃NH₂(aq) + H₂O(aq) ⇌ CH₃NH₃⁺(aq) + OH⁻
<em>(1)</em>
In equilibrium, a solution of CH₃NH₂ 4,7M produces:
[CH₃NH₂] = 4,7 - x
[CH₃NH₃⁺] = x
[OH⁻] = x
Replacing in (1):
x² + 4,38x10⁻⁴x - 2,0586x10⁻³ = 0
The solutions are:
x = -0,0456 No physical sense. There are not negative concentrations.
x = 0,04515 Real answer.
The concentration of [OH⁻] is 0,04515 M.
As pOH = -log [OH⁻] And pH+pOH = 14. The pH of this solution is:
<em>pH = 12,65</em>
The addition of 6,7M produce this changes in concentrations:
[CH₃NH₂] = 4,656 + x
[CH₃NH₃⁺] = 6,74515 - x
[OH⁻] = 0,04515 - x
Replacing in (1) you will obtain:
x² - 6,7907x + 0,3025 = 0
Solving for x:
x = 6,74586 No physical sense
x = 0,04484 Real answer.
Thus, [OH⁻] = 0,04515 - 0,044842 = 3,08x10⁻⁴M
pOH = 3,51.
<em>pH = 10,49</em>
Thus ΔpH is 12,65 - 10,49 = <em>2,16 ≈ 2,17</em>
I hope it helps!
9 grams of hydrogen gas (H2) will SC Johnson need to react in order to make 1 bottle of Windex.
Explanation:
Balance equation for the formation of ammonia from H2 gas.
N2 + 3H2 ⇒ 2
Given
mass of ammonia in 1 bottle of windex = 51 gram
atomic mass of ammonia 17.01 gram/mole
number of moles =
number of moles =
= 3 moles of ammonia is formed.
in 1 bottle of windex there are 3 moles of ammonia 0r 51 grams of ammonia.
From the equation it can be found that:
3 moles of hydrogen reacted to form 2 moles of ammonia
so, x moles of hydrogen will react to form 3 moles of ammonia.
=
x = 4.5 moles of hydrogen will be required.
to convert moles into gram formula used:
mass = atomic mass x number of moles (atomic mass of H2 is 2grams/mole)
= 2 x 4.5
= 9 grams of hydrogen.