Answer:
K = 2 × 10⁻⁷²
Explanation:
Step 1. Determine the value of n
Zn²⁺ + 2e⁻ → Zn
2Cl⁻ → Cl₂+ 2e⁻
Zn²⁺ + 2Cl⁻ → Zn + Cl₂; E = -2.12 V
n = 2 mol electrons
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Step 2. Calculate K
The formula relating E and K is
E = (RT)/(nF)lnK
E = -2.12 V
R = 8.314 J·K⁻¹mol⁻¹
T = 298.15 K
n = 2
F = 96 485 C/mol
-2.12 = (8.314 × 298.15)/(2 × 96 485)lnK Do the multiplications
-2.12 = 2479/192 970 lnK Do the division
-2.12 = 0.012 85 lnK Divide both sides by 0.012 85 and transpose
ln K = -165.0 Take the antilog of both sides
K = 2 × 10⁻⁷²
B.) exposure to seasonal changes
C.) exposure to human activity
D.) exposure to moonlight
B. An atom is entirely solid and has no empty spaces between its particles.
C. An atom has a dense nucleus surrounded by mostly empty space where electrons travel.
b. 0.04.
c. 0.05.
d. 0.08
This question is based on the concept of percentage by mass. Therefore the value of x, concentration of unknown ethanol solution is 4% when 20 gallons of a known solution is used. Option b is correct option
Mass percentage represents the the percentage of each element that is making a particular compound. Mass percentage does not have any unit as numerator and denominator contains the same unit.
Mathematically,
Percentage of mass = (component’s mass ÷ total mass) x 100%
According to the question the equation can be written as:
20× (x÷ 100) + 60×0.12 = 80× 0.10
x÷5 + 7.2 = 8
x÷ 5 = 0.8
x = 4%
concentration of unknown solution = 4%
Therefore, the value of x, concentration of unknown ethanol solution is 4% when 20 gallons of a solution is used. Option b is correct option
To learn more about mass percentage, here:
#SPJ5
the correct answer is B
Carbon-12 Atom is correct :)