The stronger the pull of gravity the greater the mass
Answer:
0.075
Explanation:
First obtain the mean of the measurement;
Mean = 10.15 + 9.95 + 9.99 + 10.02/4 = 10.03
Then obtain d^2= (mean-score)^2 for each score;
(10.15-10.03)^2 = 0.0144
(9.95-10.03)^2 = 0.0064
(9.99-10.03)^2 = 0.0016
(10.02-10.03)^2= 0.0001
∑d^2= 0.0144 + 0.0064 + 0.0016 + 0.0001
∑d^2= 0.0225
Variance = ∑d^2/N = 0.0225/4 = 0.005625
Standard deviation= √0.005625
Standard deviation= 0.075
Answer:
37 mmol of acetate need to add to this solution.
Explanation:
Acetic acid is an weak acid. According to Henderson-Hasselbalch equation for a buffer consist of weak acid (acetic acid) and its conjugate base (acetate)-
![pH=pK_{a}(acetic acid)+log[\frac{mmol of CH_{3}COO^{-}}{mmol of CH_{3}COOH }]](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%28acetic%20acid%29%2Blog%5B%5Cfrac%7Bmmol%20of%20CH_%7B3%7DCOO%5E%7B-%7D%7D%7Bmmol%20of%20CH_%7B3%7DCOOH%20%7D%5D)
Here pH is 5.31,
(acetic acid) is 4.74 and number of mmol of acetic acid is 10 mmol.
Plug in all the values in the above equation:
![5.31=4.74+log[\frac{mmol of CH_{3}COO^{-}}{10}]](https://tex.z-dn.net/?f=5.31%3D4.74%2Blog%5B%5Cfrac%7Bmmol%20of%20CH_%7B3%7DCOO%5E%7B-%7D%7D%7B10%7D%5D)
or, mmol of
= 37
So 37 mmol of acetate need to add to this solution.