Use stoichiometry 3.75moles k* 39.10g k\1 mole k= 146.63g k
<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>
Answer: 3
Explanation:
An oxide-reduction reaction or, simply, redox reaction, is a <u>chemical reaction in which one or more electrons are transferred between the reactants</u>, causing a change in their oxidation states, which is the hypothetical electric charge that the atom would have if all its links with different elements were 100% ionic.
For there to be a reduction-oxidation reaction, in the system there must be an element that yields electrons and another that accepts them:
-
The oxidizing agent picks up electrons and remains with a state of oxidation inferior to that which it had, that is, it is reduced.
- The reducing agent supplies electrons from its chemical structure to the medium, increasing its oxidation state, ie, being oxidized.
To balance a redox equation you must <u>identify the elements that are oxidized and reduced and the amount of electrons that they release or capture, respectively.
</u>
In the reaction that arises in the question the silver (Ag) is reduced <u>because it decreases its oxidation state from +1 to 0</u> and the aluminum (Al) is oxidized because <u>its oxidation state increases from 0 to +3</u>, releasing 3 electrons (e⁻). Then we can raise two half-reactions:
Ag⁺ + e⁻ → Ag⁰
Al⁰ → Al⁺³ + 3e⁻
In order to obtain the balanced equation, we must multiply the first half-reaction by 3 so that, when both half-reactions are added, the electrons are canceled. In this way:
(Ag⁺ + e⁻ → Ag⁰ ) x3
Al⁰ → Al⁺³ + 3e⁻ +
-------------------------------------
3Ag⁺ + Al⁰ → 3Ag⁰ + Al⁺³
So, the coefficient of silver in the final balanced equation is 3.
For this reaction: ΔG⁰>0.
Balanced chemical reaction A(g) ⇌ (g)
ΔG° indicates that all reactants and products are in their standard states.
ΔG° = R·T·lnK.
ΔG° is Gibbs free energy
T is the temperature on the Kelvin scale
R is the ideal gas constant
The equilibrium constant (K) is the ratio of the partial pressures or the concentrations of products to reactants.
Gibbs free energy (G) determines if reaction will proceed spontaneously, nonspontaneously or in equilibrium processes.
If K < 1, than ΔG° > 0.
Reactants (in this example A) are favored over products (in this example B) at equilibrium.
More about equilibrium: brainly.com/question/25651917:
#SPJ4
Answer:
specific heat.
Explanation:
Definition:
The amount of heat required to raise the temperature of one gram of substance by one degree is called specific heat.
Formula:
Q = m. c. ΔT
Q = amount of heat required
m = mass of substance
c = specific heat of substance
ΔT = change in temperature
The substance with greater value of specific heat require more heat to raise the temperature while the substance with lower value will raise its temperature very quickly by absorbing smaller heat.
For example the beach sand gets hot very quickly because of lower specific heat of sand while water is colder than sand because of higher specific heat capacity.
