<span>Answer:
The half-reaction is as followed:
Cr2O72â’(aq) + 14H+ + 6e⒠→ 2Cr3+(aq) + 7H2O
From the half-reaction, you can retrieve the following information:
1 mole of potassium dichromate =6 moles of e^-
6 moles of e^-=2 moles of Cr
You will also need the following information:
1 mole of e^-=96,485 C
and
1 mole of Cr=52.00g
Calculate the number of moles that 4.94mg equates too:
4.94 mg=4.94 x 10^-3g of chromium*(1 mol/52.00g)=9.50 x 10^-5 mole of Cr
How many moles of electrons are need to produce 9.50 x 10^-5 mole of Cr? Solve for moles of electrons:
9.50 x 10^-5 mole of Cr*(6 moles of e^-/2 mole of Cr)=2.85 x 10^-4 moles of e^-
Whats the charge of 2.85 x 10^-4 moles of electrons? Use Faraday's constant:
2.85 x 10^-4 moles of e^-*(96,485 C/1 mole of e^-)=2.750 x 10^1 C
Since current (A)=charge (C)/time (s), solve for time:
A=C/s
C/A=s
2.750 x 10^1 C/0.234 A=time (s)
1.18 x 10^2 s=118s=time <= 3 significant figures</span>
Consider the following equilibrium:
4NH₃ (g) + 3O₂ (g) ⇄ 2N₂ (g) + 6H₂O (g) + 1531 kJ
The given statement is True, because
According to Le Ch's Principle:
Systems that have attained the state of chemical equilibrium will tend to maintain their equilibrium state.
External factors such as the addition of products and reactants result in the disruption of the equilibrium state.
we expect the system to shift to the direction that offsets the change in concentration.
This results in the state of chemical equilibrium to be reestablished.
Hence, The statement is true,
- The addition of more ammonia (a reactant) would offset the state of equilibrium.
- To restore chemical equilibrium, the system must consume the excess reactants to form more products.
- A shift to favor the products side occurs.
To learn more about equilibrium here
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Matter either loses or absorbs energy when it changes from one state to another.
2 NH3 -> 1 N2 + 3 H2
Explanation:
That would be the answer to this
