Answer: It will take 11.775 seconds.
Explanation: As a sphere with a diameter of 0.1 mm, the area of an alveolus is
A = 4.π.r²
r for an alveolus would be: r = 0.00005m or r = 5.
m
Finding the area:
A = 4.3.14.(5.)²
A = 3.14.
m²
The concentration change is to be 90% of the final, so
c = 0.9.3.14.
c = 28.26.
The oxygen diffusivity is 2.4.m²/s, that means in 1 second 2.4. of oxygen spread in one alveolus area. So:
1 second = 2.4.m²
t seconds = 28.26.m²
t = 
t = 11.775s
For a concentration change at the center to be 90%, it will take 11.775s.
Answer:
digital signal is the answer
Answer:
2.
independent variable:amount of water
dependent variable:plant growth
3.
independent variable:student's bedtime
dependent variable: students energy level
4.
independent variable:exercise
dependent variable: strength
5.
independent variable:persons height
dependent variable:ability to play basketball
Explanation:
Answer:
56.9 mmoles of acetate are required in this buffer
Explanation:
To solve this, we can think in the Henderson Hasselbach equation:
pH = pKa + log ([CH₃COO⁻] / [CH₃COOH])
To make the buffer we know:
CH₃COOH + H₂O ⇄ CH₃COO⁻ + H₃O⁺ Ka
We know that Ka from acetic acid is: 1.8×10⁻⁵
pKa = - log Ka
pKa = 4.74
We replace data:
5.5 = 4.74 + log ([acetate] / 10 mmol)
5.5 - 4.74 = log ([acetate] / 10 mmol)
0.755 = log ([acetate] / 10 mmol)
10⁰'⁷⁵⁵ = ([acetate] / 10 mmol)
5.69 = ([acetate] / 10 mmol)
5.69 . 10 = [acetate] → 56.9 mmoles
