Chemistry, 07.12.2019 21:31, hewonabi123

Calculate the cd^2+ concentration in the following cell if ecell = 0.23

cd | cd^2+ (x m) || ni^2+ (1.00 m) | ni

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answered: bre644

$\large \boxed{\text{1.14 $\times 10^{-3}$ mol/L}}$

Explanation:

We must use the Nernst equation

$E = E^{\circ} - \dfrac{RT}{zF}\ln Q$

Step 1. Calculate E°

Anode: Cd ⟶ Cd²⁺(x mol·L⁻¹) + 2e⁻; E° = +0.4030 V

Cathode: Ni²⁺ (1.00 mol·L⁻¹) + 2e⁻ ⟶ Ni; E° = - 0.257 V

Overall: Ni²⁺(1.00 mol·L⁻¹) + Cd ⟶ Ni + Cd²⁺ (x mol·L⁻¹); E° = 0.146 V

Step 2. Calculate Q

$\begin{array}{rcl}0.23 & = & 0.146 - \dfrac{8.314\times 298}{2 \times 96 485} \ln Q\\\\0.084& = & -0.01284 \ln Q\\\ln Q & = & -6.542\\Q & = & e^{-6.542}\\ & = &1.14 \times 10^{-3}\\\end{array}$

3. Calculate [Cd²⁺]

$\begin{array}{rcl}Q & = & \dfrac{\text{[Cd$^{2+}$]}}{\text{[Ni}^{2+}]}\\\\1.14 \times 10^{-3} & = & \dfrac{x}{1.00}\\\\x& = & 1.14 \times 10^{-3}\\\end{array}\\\text{The concentration of Cd$^{2+}$ is $\large \boxed{\textbf{1.14 $\times \mathbf{10^{-3}}$ mol/L}}$}$

answered: Guest

wanahton purified a portion of water with 900 grams of contaminants. each hour, a third of the contaminants was filtered out.

let g(n) be the amount of contaminants (in grams) that remained by the beginning of the nth hour. g is a sequence, what kind of sequence is it, arithmetic or geometric? then, write an explicit formula for the sequence, g(n)=

wanahton purified a portion of water with 900 grams of contaminants. each hour, a third of the contaminants was filtered out.

explanation:

answered: Guest

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